Calculating scattering matrices by wave function matching
Energy Technology Data Exchange (ETDEWEB)
Zwierzycki, M. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan (Poland); Khomyakov, P.A.; Starikov, A.A.; Talanana, M.; Xu, P.X.; Karpan, V.M.; Marushchenko, I.; Brocks, G.; Kelly, P.J. [Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Xia, K. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Turek, I. [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, 616 62 Brno (Czech Republic); Bauer, G.E.W. [Kavli Institute of NanoScience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)
2008-04-15
The conductance of nanoscale structures can be conveniently related to their scattering properties expressed in terms of transmission and reflection coefficients. Wave function matching (WFM) is a transparent technique for calculating transmission and reflection matrices for any Hamiltonian that can be represented in tight-binding form. A first-principles Kohn-Sham Hamiltonian represented on a localized orbital basis or on a real space grid has such a form. WFM is based upon direct matching of the scattering-region wave function to the Bloch modes of ideal leads used to probe the scattering region. The purpose of this paper is to give a pedagogical introduction to WFM and present some illustrative examples of its use in practice. We briefly discuss WFM for calculating the conductance of atomic wires, using a real space grid implementation. A tight-binding muffin-tin orbital implementation very suitable for studying spin-dependent transport in layered magnetic materials is illustrated by looking at spin-dependent transmission through ideal and disordered interfaces. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Efficient wave-function matching approach for quantum transport calculations
DEFF Research Database (Denmark)
Sørensen, Hans Henrik Brandenborg; Hansen, Per Christian; Petersen, Dan Erik
2009-01-01
The wave-function matching (WFM) technique has recently been developed for the calculation of electronic transport in quantum two-probe systems. In terms of efficiency it is comparable to the widely used Green's function approach. The WFM formalism presented so far requires the evaluation of all ...
Flammer, Carson
2005-01-01
Intended to facilitate the use and calculation of spheroidal wave functions, this applications-oriented text features a detailed and unified account of the properties of these functions. Addressed to applied mathematicians, mathematical physicists, and mathematical engineers, it presents tables that provide a convenient means for handling wave problems in spheroidal coordinates.Topics include separation of the scalar wave equation in spheroidal coordinates, angle and radial functions, integral representations and relations, and expansions in spherical Bessel function products. Additional subje
Semiclassical multicomponent wave function
Mostovoy, M.V.
1994-01-01
A consistent method for obtaining the semiclassical multicomponent wave function for any value of adiabatic parameter is discussed and illustrated by examining the motion of a neutral particle in a nonuniform magnetic field. The method generalizes the Bohr-Sommerfeld quantization rule to
DEFF Research Database (Denmark)
Dahl, Jens Peder; Varro, S.; Wolf, A.
2007-01-01
We derive explicit expressions for the Wigner function of wave functions in D dimensions which depend on the hyperradius-that is, of s waves. They are based either on the position or the momentum representation of the s wave. The corresponding Wigner function depends on three variables......: the absolute value of the D-dimensional position and momentum vectors and the angle between them. We illustrate these expressions by calculating and discussing the Wigner functions of an elementary s wave and the energy eigenfunction of a free particle....
Directory of Open Access Journals (Sweden)
Y. Zhu
2017-04-01
Full Text Available High Frequency (HF radio waves propagating in the ionospheric random inhomogeneous media exhibit a spatial nonlinearity wavefront which may limit the performance of conventional high-resolution methods for HF sky wave radar systems. In this paper, the spatial correlation function of wavefront is theoretically derived on condition that the radio waves propagate through the ionospheric structure containing irregularities. With this function, the influence of wavefront distortions on the array covariance matrix can be quantitatively described with the spatial coherence matrix, which is characterized with the coherence loss parameter. Therefore, the problem of wavefront correction is recast as the determination of coherence loss parameter and this is solved by the covariance matching (CM technique. The effectiveness of the proposed method is evaluated both by the simulated and real radar data. It is shown numerically that an improved direction of arrival (DOA estimation performance can be achieved with the corrected array covariance matrix.
Lienert, Matthias; Petrat, Sören; Tumulka, Roderich
2017-08-01
In non-relativistic quantum mechanics of N particles in three spatial dimensions, the wave function ψ( q 1, …, q N , t) is a function of 3N position coordinates and one time coordinate. It is an obvious idea that in a relativistic setting, such functions should be replaced by ϕ((t 1, q 1), …, (tN, q N )), a function of N space-time points called a multi-time wave function because it involves N time variables. Its evolution is determined by N Schrödinger equations, one for each time variable; to ensure that simultaneous solutions to these N equations exist, the N Hamiltonians need to satisfy a consistency condition. This condition is automatically satisfied for non-interacting particles, but it is not obvious how to set up consistent multi-time equations with interaction. For example, interaction potentials (such as the Coulomb potential) make the equations inconsistent, except in very special cases. However, there have been recent successes in setting up consistent multi-time equations involving interaction, in two ways: either involving zero-range (δ potential) interaction or involving particle creation and annihilation. The latter equations provide a multi-time formulation of a quantum field theory. The wave function in these equations is a multi-time Fock function, i.e., a family of functions consisting of, for every n = 0, 1, 2, …, an n-particle wave function with n time variables. These wave functions are related to the Tomonaga-Schwinger approach and to quantum field operators, but, as we point out, they have several advantages.
Explosion yield estimation from pressure wave template matching
Arrowsmith, Stephen; Bowman, Daniel
2017-01-01
A method for estimating the yield of explosions from shock-wave and acoustic-wave measurements is presented. The method exploits full waveforms by comparing pressure measurements against an empirical stack of prior observations using scaling laws. The approach can be applied to measurements across a wide-range of source-to-receiver distances. The method is applied to data from two explosion experiments in different regions, leading to mean relative errors in yield estimates of 0.13 using prior data from the same region, and 0.2 when applied to a new region. PMID:28618805
[Study on phase-matching of four-wave mixing spectrum in photonic crystal fiber].
Liu, Xiao-xu; Wang, Shu-tao; Zhao, Xing-tao; Chen, Shuang; Zhou, Gui-yao; Wu, Xi-jun; Li, Shu-guang; Hou, Lan-Tian
2014-06-01
In the present paper, the four-wave mixing principle of fiber was analyzed, and the high-gain phase-matching conditions were shown. The nonlinear coefficient and dispersion characteristics of photonic crystal fibers were calculated by multipole method. The phase mismatch characteristics of fibers with multiple zero-dispersion wavelengths were analyzed for the first time. The changing rules of phase matching wavelength with the pump wavelength and the pump power were obtained, and the phase matching curves were shown. The characteristics of phase matching wavelengths for different dispersion curves were analyzed. There are four new excitation wavelengths of four-wave mixing spectrum in two zero-dispersion wavelength photonic crystal fiers. Four-wave mixing spectroscopy of photonic crystal fibers with two zero-dispersion wavelengths was obtained in the experi-ent, which is consistent with the theoretical analysis, and verified the reliability of the phase matching theory. The fiber with multiple zero-dispersion wavelengths can create a ricbhphase-matching topology, excite more four-wave mixing wavelengths, ena-ling enhanced control over the spectral locations of the four-wave mixing and resonant-radiation bands emitted by solitons and short pulses. These provide theoretical guidance for photonic crystal fiber wavelength conversion and supercontinoum generation based on four-wave mixing.
Sternini, S.; Quattrocchi, A.; Montanini, R.; Lanza di Scalea, F.
2017-04-01
Damage imaging of structural components in the field of Non Destructive Evaluations (NDE) and Structural Health Monitoring (SHM) using ultrasonic waves is usually performed by conventional imaging techniques, such as DelayAnd-Sum (DAS), by back-propagating the recorded waveforms to identify locations and size of defects and damages. This technique results in sidelobes and artifacts that worsen the accuracy of the damage identification. Here we propose a novel imaging approach that derives from the well-known technique of Matched Field Processing (MFP), often used in underwater acoustics and seismology. In MFP, the source or damage is located by a matching procedure between measurements ("data vector") and expected responses ("replica vectors") computed for each point of the imaging volume. In this work, we apply this matching approach only to selected features extracted from the recorded waveforms. These features, for example time-of-flights or amplitudes, will be selected for multiple modes of propagation of the ultrasonic waves (longitudinal and shear in bulk waves, multiple guided modes in waveguides). By considering multiple features and multiple wave modes, it is possible to increase the performance of this matching procedure, which can be possibly further improved by also combining different signal frequencies and excitation sources in analogy with biomedical ultrasonic imaging. A correlation metric showing high computational efficiency in the image reconstruction process will be tested as matching coefficient. Applications of this imaging approach to a metallic plate with holes and simulated defects will be shown.
Baart, Martijn; Bortfeld, Heather; Vroomen, Jean
2015-01-01
The correspondence between auditory speech and lip-read information can be detected based on a combination of temporal and phonetic cross-modal cues. Here, we determined the point in developmental time at which children start to effectively use phonetic information to match a speech sound with one of two articulating faces. We presented 4- to 11-year-olds (N=77) with three-syllabic sine-wave speech replicas of two pseudo-words that were perceived as non-speech and asked them to match the sounds with the corresponding lip-read video. At first, children had no phonetic knowledge about the sounds, and matching was thus based on the temporal cues that are fully retained in sine-wave speech. Next, we trained all children to perceive the phonetic identity of the sine-wave speech and repeated the audiovisual (AV) matching task. Only at around 6.5 years of age did the benefit of having phonetic knowledge about the stimuli become apparent, thereby indicating that AV matching based on phonetic cues presumably develops more slowly than AV matching based on temporal cues. Copyright © 2014 Elsevier Inc. All rights reserved.
Prism-coupled Cherenkov phase-matched terahertz wave generation using a DAST crystal.
Suizu, Koji; Shibuya, Takayuki; Uchida, Hirohisa; Kawase, Kodo
2010-02-15
Terahertz (THz) wave generation based on nonlinear frequency conversion is a promising method for realizing a tunable monochromatic high-power THz-wave source. Unfortunately, many nonlinear crystals have strong absorption in the THz frequency region. This limits efficient and widely tunable THz-wave generation. The Cherenkov phase-matching method is one of the most promising techniques for overcoming these problems. Here, we propose a prism-coupled Cherenkov phase-matching (PCC-PM) method, in which a prism with a suitable refractive index at THz frequencies is coupled to a nonlinear crystal. This has the following advantages. Many crystals can be used as THz-wave emitters; the phase-matching condition inside the crystal does not have to be observed; the absorption of the crystal does not prevent efficient generation of radiation; and pump sources with arbitrary wavelengths can be employed. Here we demonstrate PCC-PM THz-wave generation using the organic crystal 4-dimethylamino-N-metyl-4-stilbazolium tosylate (DAST) and a Si prism coupler. We obtain THz-wave radiation with tunability of approximately 0.1 to 10 THz and with no deep absorption features resulting from the absorption spectrum of the crystal. The obtained spectra did not depend on the pump wavelength in the range 1300 to 1450 nm. This simple technique shows promise for generating THz radiation using a wide variety of nonlinear crystals.
Hu, Chen-Yang; Li, Zhi-Yuan
2017-03-01
We develop an effective nonlinear susceptibility model (ENSM) to solve analytically the general three-wave mixing nonlinear optical interaction problem under the quasi-phase-matching (QPM) scheme. The nonlinear processes including sum-frequency generation, difference-frequency generation and second harmonic generation are discussed in both periodic poled lithium niobate (PPLN) and chirped PPLN (CPPLN) structures. The analytical ENSM results show great consistency with rigorous numerical simulation based on direct solution of the nonlinear coupled-wave equations. This indicates that the ENSM is a brief, convenient, accurate, and efficient theoretical tool to quantitatively evaluate the performance of various three-wave mixing interactions in general QPM structures such as PPLN and CPPLN and to design and optimize the QPM structures for many specific functionalities of nonlinear frequency conversion.
Wind wave source functions in opposing seas
Langodan, Sabique
2015-08-26
The Red Sea is a challenge for wave modeling because of its unique two opposed wave systems, forced by opposite winds and converging at its center. We investigate the different physical aspects of wave evolution and propagation in the convergence zone. The two opposing wave systems have similar amplitude and frequency, each driven by the action of its own wind. Wave patterns at the centre of the Red Sea, as derived from extensive tests and intercomparison between model and measured data, suggest that the currently available wave model source functions may not properly represent the evolution of the local fields that appear to be characterized by a less effective wind input and an enhanced white-capping. We propose and test a possible simple solution to improve the wave-model simulation under opposing winds and waves condition. This article is protected by copyright. All rights reserved.
Raybaut, Myriam; Godard, Antoine; Toulouse, Alexis; Lubin, Clement; Rosencher, Emmanuel
2008-10-27
Fresnel phase matching is a convenient and universal way to phase match nonlinear three-wave mixing by total internal reflection in isotropic materials like common semiconductors. This technique makes use of the large relative phase lag between the interacting waves at total internal reflection, and was suggested by the nonlinear optics pioneers in the 70's; it has been worked out by several teams since then but, quite unexpectedly, has never succeeded in producing enough parametric gain to achieve optical parametric oscillation. We show that this failure stems mostly from a basic law of nonlinear reflection, which leads to a spatial walk-off between the pump and the generated parametric waves, resulting in unexpected destructive interference patterns between the waves while bouncing back and forth between the interfaces. Ray tracing or plane wave analysis gives an incomplete representation of the phenomenon while highly multimodal nonlinear guided wave theory reconciles the different views. Very good agreement between the presented theory and experiments is demonstrated in gallium arsenide samples.
Detailed phase matching characterization of inter-modal four-wave mixing in a two-mode fiber
DEFF Research Database (Denmark)
Friis, Søren Michael Mørk; Jung, Y.; Begleris, I.
2016-01-01
We experimentally characterize the phase matching properties of two inter-modal four-wave mixing processes in a graded index fiber guiding the LP01 and LP11 mode-groups.......We experimentally characterize the phase matching properties of two inter-modal four-wave mixing processes in a graded index fiber guiding the LP01 and LP11 mode-groups....
Izumi, FURUOYA; Department of Physics, Hosei University
1982-01-01
The effect of the intermediate structure, the doorway state, on the overall aspect of the p-wave strength function plotted with respect to mass number is investigated. Our qualitative method is analogous to that used by Block and Feshbach in their investigation on the s-wave strength function. It is shown that low values in the p-wave strength function near A=50 and A=160 can be explained by our theory. In particular it is found that the change of the number of doorway states contributing to ...
Data-driven matched field processing for Lamb wave structural health monitoring.
Harley, Joel B; Moura, José M F
2014-03-01
Matched field processing is a model-based framework for localizing targets in complex propagation environments. In underwater acoustics, it has been extensively studied for improving localization performance in multimodal and multipath media. For guided wave structural health monitoring problems, matched field processing has not been widely applied but is an attractive option for damage localization due to equally complex propagation environments. Although effective, matched field processing is often challenging to implement because it requires accurate models of the propagation environment, and the optimization methods used to generate these models are often unreliable and computationally expensive. To address these obstacles, this paper introduces data-driven matched field processing, a framework to build models of multimodal propagation environments directly from measured data, and then use these models for localization. This paper presents the data-driven framework, analyzes its behavior under unmodeled multipath interference, and demonstrates its localization performance by distinguishing two nearby scatterers from experimental measurements of an aluminum plate. Compared with delay-based models that are commonly used in structural health monitoring, the data-driven matched field processing framework is shown to successfully localize two nearby scatterers with significantly smaller localization errors and finer resolutions.
A Novel 3D Viscoelastic Acoustic Wave Equation Based Update Method for Reservoir History Matching
Katterbauer, Klemens
2014-12-10
The oil and gas industry has been revolutionized within the last decade, with horizontal drilling and hydraulic fracturing enabling the extraction of huge amounts of shale gas in areas previously considered impossible and the recovering of hydrocarbons in harsh environments like the arctic or in previously unimaginable depths like the off-shore exploration in the South China sea and Gulf of Mexico. With the development of 4D seismic, engineers and scientists have been enabled to map the evolution of fluid fronts within the reservoir and determine the displacement caused by the injected fluids. This in turn has led to enhanced production strategies, cost reduction and increased profits. Conventional approaches to incorporate seismic data into the history matching process have been to invert these data for constraints that are subsequently employed in the history matching process. This approach makes the incorporation computationally expensive and requires a lot of manual processing for obtaining the correct interpretation due to the potential artifacts that are generated by the generally ill-conditioned inversion problems. I have presented here a novel approach via including the time-lapse cross-well seismic survey data directly into the history matching process. The generated time-lapse seismic data are obtained from the full wave 3D viscoelastic acoustic wave equation. Furthermore an extensive analysis has been performed showing the robustness of the method and enhanced forecastability of the critical reservoir parameters, reducing uncertainties and exhibiting the benefits of a full wave 3D seismic approach. Finally, the improved performance has been statistically confirmed. The improvements illustrate the significant improvements in forecasting that are obtained via readily available seismic data without the need for inversion. This further optimizes oil production in addition to increasing return-on-investment on oil & gas field development projects, especially
Geometric entanglement in the Laughlin wave function
Zhang, Jiang-Min; Liu, Yu
2017-08-01
We study numerically the geometric entanglement in the Laughlin wave function, which is of great importance in condensed matter physics. The Slater determinant having the largest overlap with the Laughlin wave function is constructed by an iterative algorithm. The logarithm of the overlap, which is a geometric quantity, is then taken as a geometric measure of entanglement. It is found that the geometric entanglement is a linear function of the number of electrons to a good extent. This is especially the case for the lowest Laughlin wave function, namely the one with filling factor of 1/3. Surprisingly, the linear behavior extends well down to the smallest possible value of the electron number, namely, N = 2. The constant term does not agree with the expected topological entropy. In view of previous works, our result indicates that the relation between geometric entanglement and topological entropy is very subtle.
A novel matching network employing surface acoustic wave devices for W-CDMA power amplifiers.
Li, Honglang; He, Songbai; Hashimoto, Ken-ya; Omori, Tatsuya; Yamaguchi, Masatsune
2006-12-22
This paper describes a new approach of designing high Q surface acoustic wave (SAW) resonators as an inductive element in the matching network for W-CDMA power amplifiers (PAs). Spiral inductors based on CMOS/BiCMOS technologies presently possess relatively low Q (typically <10) and occupy a considerably large area. In order to break through the limitations of the spiral inductors, the authors attempt to apply higher Q and wideband SAW resonators employing Cu-grating/15 degrees YX-LiNbO(3)-substrate structure to the matching network for improved PA performance. An analysis was made on SAW resonators in detail, and an SAW resonator having a very small capacitance ratio of 3.28 and moderate Q of 147.8 was developed. After discussing the frequency dependence of the effective inductances, SAW resonators, which are used to be as inductive elements in the matching networks of PAs, were designed and fabricated. The PA including the matching circuit was simulated using the characteristics of the fabricated SAW resonators. The result showed that with better shape factor and good out-of-rejection, the SAW resonators definitely work as an inductive element and could replace widely used spiral inductors.
Twist-2 Light-Cone Pion Wave Function
Belyaev, V. M.; Johnson, Mikkel B.
1997-01-01
We present an analysis of the existing constraints for the twist-2 light-cone pion wave function. We find that existing information on the pion wave function does not exclude the possibility that the pion wave function attains its asymptotic form. New bounds on the parameters of the pion wave function are presented.
Matched Template Signal Processing for Continuous Wave Laser Tracking of Space Debris
Raj, S.; Ward, R.; Roberts, L.; Fleddermann, R.; Francis, S.; McClellend, D.; Shaddock, D.; Smith, C.
2016-09-01
The build up of space junk in Earth's orbit space is a growing concern as it shares the same orbit as many currently active satellites. As the number of objects increase in these orbits, the likelihood of collisions between satellites and debris will increase [1]. The eventual goal is to be able to maneuver space debris to avoid such collisions. We at SERC aim to accomplish this by using ground based laser facilities that are already being used to track space debris orbit. One potential method to maneuver space debris is using continuous wave lasers and applying photon pressure on the debris and attempt to change the orbit. However most current laser ranging facilities operates using pulsed lasers where a pulse of light is sent out and the time taken for the pulse to return back to the telescope is measured after being reflected by the target. If space debris maneuvering is carried out with a continuous wave laser then two laser sources need to be used for ranging and maneuvering. The aim of this research is to develop a laser ranging system that is compatible with the continuous wave laser; using the same laser source to simultaneously track and maneuver space debris. We aim to accomplish this by modulating the outgoing laser light with pseudo random noise (PRN) codes, time tagging the outgoing light, and utilising a matched filter at the receiver end to extract the various orbital information of the debris.
Multifractal wave functions of simple quantum maps.
Martin, John; García-Mata, Ignacio; Giraud, Olivier; Georgeot, Bertrand
2010-10-01
We study numerically multifractal properties of two models of one-dimensional quantum maps: a map with pseudointegrable dynamics and intermediate spectral statistics and a map with an Anderson-like transition recently implemented with cold atoms. Using extensive numerical simulations, we compute the multifractal exponents of quantum wave functions and study their properties, with the help of two different numerical methods used for classical multifractal systems (box-counting and wavelet methods). We compare the results of the two methods over a wide range of values. We show that the wave functions of the Anderson map display a multifractal behavior similar to eigenfunctions of the three-dimensional Anderson transition but of a weaker type. Wave functions of the intermediate map share some common properties with eigenfunctions at the Anderson transition (two sets of multifractal exponents, with similar asymptotic behavior), but other properties are markedly different (large linear regime for multifractal exponents even for strong multifractality, different distributions of moments of wave functions, and absence of symmetry of the exponents). Our results thus indicate that the intermediate map presents original properties, different from certain characteristics of the Anderson transition derived from the nonlinear sigma model. We also discuss the importance of finite-size effects.
Electronic Structure of Matter Wave Functions and Density Functionals.
Kohn, W
1999-01-01
Since the 1920's Schroedinger wave functions have been the principal theoretical concept for understanding and computing the electronic structure of matter. More recently, Density Functional Theory (DFT), couched in terms of the electronic density distribution, n(r), has provided a new perspective and new computational possibilities, especially for systems consisting of very many (up to ~1000) atoms. In this talk some fundamental limitations of wave function methods for very-many-atom-systems will be discussed. The DFT approach will be explained together with some physical/chemical applications and a discussion of its strenghts and weaknesses.
Study of Ion Acoustic Wave Damping through Green's Functions
DEFF Research Database (Denmark)
Hsuan, H.C.S.; Jensen, Vagn Orla
1973-01-01
Green's function analyses of ion acoustic waves in streaming plasmas show that, in general, the waves damp algebraically rather than exponentially with distance from exciter.......Green's function analyses of ion acoustic waves in streaming plasmas show that, in general, the waves damp algebraically rather than exponentially with distance from exciter....
Gao, Shiming; Yang, Changxi; Jin, Guofan
2003-12-20
We investigate power-dependent phase-matched four-wave mixing (FWM) in wavelength division multiplexing transmission lines, in which positive and negative dispersion fibers are alternately arranged to manage the dispersion and the dispersion slope. The FWM effect shows power-independent phase matching when the channel power is low. However, it is power dependent at high power. The maximum FWM conversion efficiency is shifted away from the zero channel space in the case of power-dependent phase matching. Optimization of the dispersion system for suppression of the FWM effect is determined.
A perfectly matched layer for the time-dependent wave equation in heterogeneous and layered media
Duru, Kenneth
2014-01-01
A mathematical analysis of the perfectly matched layer (PML) for the time-dependent wave equation in heterogeneous and layered media is presented. We prove the stability of the PML for discontinuous media with piecewise constant coefficients, and derive energy estimates for discontinuous media with piecewise smooth coefficients. We consider a computational setup consisting of smaller structured subdomains that are discretized using high order accurate finite difference operators for approximating spatial derivatives. The subdomains are then patched together into a global domain by a weak enforcement of interface conditions using penalties. In order to ensure the stability of the discrete PML, it is necessary to transform the interface conditions to include the auxiliary variables. In the discrete setting, the transformed interface conditions are crucial in deriving discrete energy estimates analogous to the continuous energy estimates, thus proving stability and convergence of the numerical method. Finally, we present numerical experiments demonstrating the stability of the PML in a layered medium and high order accuracy of the proposed interface conditions. © 2013 Elsevier Inc.
Plausible Suggestion for a Deterministic Wave Function
Schulz, Petra
2006-01-01
A deterministic axial vector model for photons is presented which is suitable also for particles. During a rotation around an axis the deterministic wave function a has the following form a = ws r exp(+-i wb t). ws is either the axial or scalar spin rotation frequency (the latter is proportional to the mass), r radius of the orbit (also amplitude of a vibration arising later from the interaction by fusing of two oppositely circling photons), wb orbital angular frequency (proportional to the v...
Directory of Open Access Journals (Sweden)
Javad Rostami
2017-06-01
Full Text Available Ultrasonic guided wave is an effective tool for structural health monitoring of structures for detecting defects. In practice, guided wave signals are dispersive and contain multiple modes and noise. In the presence of overlapped wave-packets/modes and noise together with dispersion, extracting meaningful information from these signals is a challenging task. Handling such challenge requires an advanced signal processing tool. The aim of this study is to develop an effective and robust signal processing tool to deal with the complexity of guided wave signals for non-destructive testing (NDT purpose. To achieve this goal, Sparse Representation with Dispersion Based Matching Pursuit (SDMP is proposed. Addressing the three abovementioned facts that complicate signal interpretation, SDMP separates overlapped modes and demonstrates good performance against noise with maximum sparsity. With the dispersion taken into account, an overc-omplete and redundant dictionary of basic atoms based on a narrowband excitation signal is designed. As Finite Element Method (FEM was used to predict the form of wave packets propagating along structures, these atoms have the maximum resemblance with real guided wave signals. SDMP operates in two stages. In the first stage, similar to Matching Pursuit (MP, the approximation improves by adding, a single atom to the solution set at each iteration. However, atom selection criterion of SDMP utilizes the time localization of guided wave reflections that makes a portion of overlapped wave-packets to be composed mainly of a single echo. In the second stage of the algorithm, the selected atoms that have frequency inconsistency with the excitation signal are discarded. This increases the sparsity of the final representation. Meanwhile, leading to accurate approximation, as discarded atoms are not representing guided wave reflections, it simplifies extracting physical meanings for defect detection purpose. To verify the
Improved Wave-vessel Transfer Functions by Uncertainty Modelling
DEFF Research Database (Denmark)
Nielsen, Ulrik Dam; Fønss Bach, Kasper; Iseki, Toshio
2016-01-01
This paper deals with uncertainty modelling of wave-vessel transfer functions used to calculate or predict wave-induced responses of a ship in a seaway. Although transfer functions, in theory, can be calculated to exactly reflect the behaviour of the ship when exposed to waves, uncertainty in input...
Human brain networks function in connectome-specific harmonic waves.
Atasoy, Selen; Donnelly, Isaac; Pearson, Joel
2016-01-21
A key characteristic of human brain activity is coherent, spatially distributed oscillations forming behaviour-dependent brain networks. However, a fundamental principle underlying these networks remains unknown. Here we report that functional networks of the human brain are predicted by harmonic patterns, ubiquitous throughout nature, steered by the anatomy of the human cerebral cortex, the human connectome. We introduce a new technique extending the Fourier basis to the human connectome. In this new frequency-specific representation of cortical activity, that we call 'connectome harmonics', oscillatory networks of the human brain at rest match harmonic wave patterns of certain frequencies. We demonstrate a neural mechanism behind the self-organization of connectome harmonics with a continuous neural field model of excitatory-inhibitory interactions on the connectome. Remarkably, the critical relation between the neural field patterns and the delicate excitation-inhibition balance fits the neurophysiological changes observed during the loss and recovery of consciousness.
Wave Propagation Characteristics in Functionally Graded Double-Beams
Directory of Open Access Journals (Sweden)
Fatih Karacam
2017-09-01
Full Text Available The wave propagation characteristics of functionally graded (FG double-beams are investigated by use of Euler-Bernoulli beam theory. Two beams are connected by a Winkler foundation. The wave propagation characteristics like frequency, phase and group velocities are obtained for different wave numbers and material properties. Four frequencies are obtained for functionally graded double-beam system. It is obtained that flexural and axial waves are coupled for FG double-beams.
Zhang, Ying; Nitschke, Monika; Krackowizer, Antoinette; Dear, Keith; Pisaniello, Dino; Weinstein, Philip; Tucker, Graeme; Shakib, Sepehr; Bi, Peng
2017-01-01
The extreme heat wave in Australia in 2009 resulted in significantly increased number of daily deaths. The circumstances that lead to deaths during extreme heat have not been explored before in Australia. This study aims to identify the individual and community risk factors for deaths during this extreme heat wave in Adelaide. A matched case-control study was conducted. Cases were those who died in the Adelaide metropolitan area during the heat wave period. For each case, two community controls were randomly selected, matched by age and gender. Face-to-face or telephone interviews were conducted to collect data of demographic information, living environment, social support, health status and behavioural changes during the heat wave. Descriptive analysis, as well as simple and multiple conditional logistic regressions were performed. In total, 82 deaths and 164 matched community controls were included in the analysis, with a median age of 77.5 (range 26.6-100.7). The multiple logistic regression model indicated that, compared with controls, the risk of death during the heat wave was significantly increased for people living alone (AOR = 42.31, 95 % CI 2.3, 792.8) or having existing chronic heart disease (AOR = 22.4, 95 % CI 1.7, 303.0). In addition, having air conditioning in bedrooms (AOR = 0.004, 95 % CI 0.00006, 0.28) and participating in social activities more than once a week (AOR = 0.011, 95 % CI 0.0004, 0.29) indicated significant protective effects. We have identified factors that could significantly impact on the likelihood of deaths during heat waves. Our findings could assist in the development of future intervention programs and policies to reduce mortality associated with a warmer climate.
Intercellular Ca2+ Waves: Mechanisms and Function
Sanderson, Michael J.
2012-01-01
Intercellular calcium (Ca2+) waves (ICWs) represent the propagation of increases in intracellular Ca2+ through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca2+ from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs. PMID:22811430
Computer network defense through radial wave functions
Malloy, Ian J.
The purpose of this research is to synthesize basic and fundamental findings in quantum computing, as applied to the attack and defense of conventional computer networks. The concept focuses on uses of radio waves as a shield for, and attack against traditional computers. A logic bomb is analogous to a landmine in a computer network, and if one was to implement it as non-trivial mitigation, it will aid computer network defense. As has been seen in kinetic warfare, the use of landmines has been devastating to geopolitical regions in that they are severely difficult for a civilian to avoid triggering given the unknown position of a landmine. Thus, the importance of understanding a logic bomb is relevant and has corollaries to quantum mechanics as well. The research synthesizes quantum logic phase shifts in certain respects using the Dynamic Data Exchange protocol in software written for this work, as well as a C-NOT gate applied to a virtual quantum circuit environment by implementing a Quantum Fourier Transform. The research focus applies the principles of coherence and entanglement from quantum physics, the concept of expert systems in artificial intelligence, principles of prime number based cryptography with trapdoor functions, and modeling radio wave propagation against an event from unknown parameters. This comes as a program relying on the artificial intelligence concept of an expert system in conjunction with trigger events for a trapdoor function relying on infinite recursion, as well as system mechanics for elliptic curve cryptography along orbital angular momenta. Here trapdoor both denotes the form of cipher, as well as the implied relationship to logic bombs.
Regularity and approximability of electronic wave functions
Yserentant, Harry
2010-01-01
The electronic Schrödinger equation describes the motion of N-electrons under Coulomb interaction forces in a field of clamped nuclei. The solutions of this equation, the electronic wave functions, depend on 3N variables, with three spatial dimensions for each electron. Approximating these solutions is thus inordinately challenging, and it is generally believed that a reduction to simplified models, such as those of the Hartree-Fock method or density functional theory, is the only tenable approach. This book seeks to show readers that this conventional wisdom need not be ironclad: the regularity of the solutions, which increases with the number of electrons, the decay behavior of their mixed derivatives, and the antisymmetry enforced by the Pauli principle contribute properties that allow these functions to be approximated with an order of complexity which comes arbitrarily close to that for a system of one or two electrons. The text is accessible to a mathematical audience at the beginning graduate level as...
Takeya, K.; Minami, T.; Okano, H.; Tripathi, S. R.; Kawase, K.
2017-01-01
When combined with a nonlinear waveguide crystal, Cherenkov phase matching allows for highly effective generation of high power and broadband terahertz (THz) waves. Using a ridged Lithium Niobate (LiNbO3) waveguide coupled with a specially designed silicon lens, we successfully generated THz waves with intensity of approximately three orders of magnitude stronger than those from conventional photoconductive antenna. The broadband spectrum was from 0.1 THz to 7 THz with a maximum dynamic range of 80 dB. The temporal shape of time domain pulse is a regular single cycle which could be used for high depth resolution time of flight tomography. The generated THz wave can also be easily monitored by compact room-temperature THz camera, enabling us to determine the spatial characteristics of the THz propagation.
Directory of Open Access Journals (Sweden)
K. Takeya
2017-01-01
Full Text Available When combined with a nonlinear waveguide crystal, Cherenkov phase matching allows for highly effective generation of high power and broadband terahertz (THz waves. Using a ridged Lithium Niobate (LiNbO3 waveguide coupled with a specially designed silicon lens, we successfully generated THz waves with intensity of approximately three orders of magnitude stronger than those from conventional photoconductive antenna. The broadband spectrum was from 0.1 THz to 7 THz with a maximum dynamic range of 80 dB. The temporal shape of time domain pulse is a regular single cycle which could be used for high depth resolution time of flight tomography. The generated THz wave can also be easily monitored by compact room-temperature THz camera, enabling us to determine the spatial characteristics of the THz propagation.
Shock Waves and Defects in Energetic Materials, a Match Made in MD Heaven
Wood, Mitchell; Kittell, David; Yarrington, Cole; Thompson, Aidan
2017-06-01
Shock wave interactions with defects, such as pores, are known to play a key role in the chemical initiation of energetic materials. In this talk the shock response of Hexanitrostilbene (HNS) is studied through large scale reactive molecular dynamics (RMD) simulations. These RMD simulations provide a unique opportunity to elucidate mechanisms of viscoplastic pore collapse which are often neglected in larger scale hydrodynamic models. A discussion of the macroscopic effects of this viscoplastic material response, such as its role in hot spot formation and eventual initiation, will be provided. Through this work we have been able to map a transition from purely viscoplastic to fluid-like pore collapse that is a function of shock strength, pore size and material strength. In addition, these findings are important reference data for the validation of future multi-scale modeling efforts of the shock response of heterogeneous materials. Examples of how these RMD results are translated into mesoscale models will also be addressed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US DOE NNSA under Contract No. DE- AC04-94AL85000.
Turnbull, M. T.; Petrov, P. G.; Embrey, C. S.; Marino, A. M.; Boyer, V.
2013-09-01
Nondegenerate forward four-wave mixing in hot atomic vapors has been shown to produce strong quantum correlations between twin beams of light [McCormick , Opt. Lett.OPLEDP0146-959210.1364/OL.32.000178 32, 178 (2007)], in a configuration which minimizes losses by absorption. In this paper, we look at the role of the phase-matching condition in the trade-off that occurs between the efficiency of the nonlinear process and the absorption of the twin beams. To this effect, we develop a semiclassical model by deriving the atomic susceptibilities in the relevant double-Λ configuration and by solving the classical propagation of the twin-beam fields for parameters close to those found in typical experiments. These theoretical results are confirmed by a simple experimental study of the nonlinear gain experienced by the twin beams as a function of the phase mismatch. The model shows that the amount of phase mismatch is key to the realization of the physical conditions in which the absorption of the twin beams is minimized while the cross coupling between the twin beams is maintained at the level required for the generation of strong quantum correlations. The optimum is reached when the four-wave mixing process is not phase matched for fully resonant four-wave mixing.
On quantum mechanical phase-space wave functions
DEFF Research Database (Denmark)
Wlodarz, Joachim J.
1994-01-01
An approach to quantum mechanics based on the notion of a phase-space wave function is proposed within the Weyl-Wigner-Moyal representation. It is shown that the Schrodinger equation for the phase-space wave function is equivalent to the quantum Liouville equation for the Wigner distribution...
Wave-function reconstruction in a graded semiconductor superlattice
DEFF Research Database (Denmark)
Lyssenko, V. G.; Hvam, Jørn Märcher; Meinhold, D.
2004-01-01
We reconstruct a test wave function in a strongly coupled, graded well-width superlattice by resolving the spatial extension of the interband polarisation and deducing the wave function employing non-linear optical spectroscopy. The graded gap superlattice allows us to precisely control the dista...
Real no-boundary wave function in Lorentzian quantum cosmology
Dorronsoro, J. Diaz; Halliwell, J. J.; Hartle, J. B.; Hertog, T.; Janssen, O.
2017-08-01
It is shown that the standard no-boundary wave function has a natural expression in terms of a Lorentzian path integral with its contour defined by Picard-Lefschetz theory. The wave function is real, satisfies the Wheeler-DeWitt equation and predicts an ensemble of asymptotically classical, inflationary universes with nearly-Gaussian fluctuations and with a smooth semiclassical origin.
DEFF Research Database (Denmark)
Yan, Lei; Johansen, Tom Keinicke
2013-01-01
In this paper, the design of InP DHBT based millimeter-wave(mm-wave) power amplifiers(PAs) using an interstage matched cascode technique is presented. The output power of a traditional cascode is limited by the early saturation of the common-base(CB) device. The interstage matched cascode can...... be employed to improve the power handling ability through optimizing the input impedance of the CB device. The minimized power mismatch between the CB and the common-emitter(CE) devices results in an improved saturated output power. To demonstrate the technique for power amplifier designs at mm......-wave frequencies, a single-branch cascode based PA using single-finger devices and a two-way combined based PA using three-finger devices are fabricated. The single-branch design shows a measured power gain of 9.2dB and a saturated output power of 12.3dBm at 67.2GHz and the two-way combined design shows a power...
Ogawa, Hisashi; Ohdan, Hideaki; Miyata, Kazunori; Taguchi, Masahiro; Makino, Kenzo; Yonezawa, Hidehiro; Yoshikawa, Jun-Ichi; Furusawa, Akira
2016-06-10
Real-time controls based on quantum measurements are powerful tools for various quantum protocols. However, their experimental realization has been limited by mode mismatch between the temporal mode of quadrature measurement and that heralded by photon detection. Here, we demonstrate real-time quadrature measurement of a single-photon wave packet induced by photon detection by utilizing continuous temporal-mode matching between homodyne detection and an exponentially rising temporal mode. Single photons in exponentially rising modes are also expected to be useful resources for interactions with other quantum systems.
Application of the stress wave method to automatic signal matching and to statnamic predictions
Esposito, G.; Courage, W.M.G.; Foeken, R.J. van
2000-01-01
The Statnamic method is an increasingly popular technique to carry out loading tests on cast in-situ piles. The method bas proved to be a cost-effective alternative to a static loading test. As-sociated to Unloading Point Method (UPM) and to automatie signal matching, the Statnamic testing technique
Baart, M.; Bortfeld, H.; Vroomen, J.
2015-01-01
The correspondence between auditory speech and lip-read information can be detected based on a combination of temporal and phonetic cross-modal cues. Here, we determined the point in developmental time at which children start to effectively use phonetic information to match a speech sound with one
THE IMPACT OF MATCHING FUNCTIONAL ON ATROPHY MEASUREMENT FROM GEODESIC SHOOTING IN DIFFEOMORPHISMS.
Fleishman, Greg M; Thompson, Paul M
2017-01-01
Longitudinal registration has been used to map brain atrophy and tissue loss patterns over time, in both healthy and demented subjects. However, we have not seen a thorough application of the geodesic shooting in diffeomorphisms framework for this task. The registration model is complex and several choices must be made that may significantly impact the quality of results. One of these decisions is which image matching functional should drive the registration. We investigate four matching functionals for atrophy quantification using geodesic shooting in diffeomorphisms. We check if the choice of matching functional has an impact on the correlation of atrophy scores with clinical variables. We also check the impact of matching functional choice on estimates of the N80 sample size for hypothetical clinical trials that test for slowing of brain atrophy. We find that the mutual information function, which has primarily been used for linear and multi-modal registration, achieves comparable correlation with clinical variables to other matching functionals while yielding better sample size estimates.
Gerini, G.; Maci, S.; Bruni, S.; Llombart, N.; Neto, A.
2005-01-01
Problem matched basis functions are proposed for the method of moments analysis of printed slot coupled microstrips. The appropriate equivalent currents of the integral equation kernel are represented in terms of two sets of entire domain basis functions. These functions synthesize on one hand the
Multi-Time Wave Functions Versus Multiple Timelike Dimensions
Lienert, Matthias; Petrat, Sören; Tumulka, Roderich
2017-12-01
Multi-time wave functions are wave functions for multi-particle quantum systems that involve several time variables (one per particle). In this paper we contrast them with solutions of wave equations on a space-time with multiple timelike dimensions, i.e., on a pseudo-Riemannian manifold whose metric has signature such as {+}{+}{-}{-} or {+}{+}{-}{-}{-}{-}{-}{-}, instead of {+}{-}{-}{-}. Despite the superficial similarity, the two behave very differently: whereas wave equations in multiple timelike dimensions are typically mathematically ill-posed and presumably unphysical, relevant Schrödinger equations for multi-time wave functions possess for every initial datum a unique solution on the spacelike configurations and form a natural covariant representation of quantum states.
The Green-function transform and wave propagation
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Colin eSheppard
2014-11-01
Full Text Available Fourier methods well known in signal processing are applied to three-dimensional wave propagation problems. The Fourier transform of the Green function, when written explicitly in terms of a real-valued spatial frequency, consists of homogeneous and inhomogeneous components. Both parts are necessary to result in a pure out-going wave that satisfies causality. The homogeneous component consists only of propagating waves, but the inhomogeneous component contains both evanescent and propagating terms. Thus we make a distinction between inhomogeneous waves and evanescent waves. The evanescent component is completely contained in the region of the inhomogeneous component outside the k-space sphere. Further, propagating waves in the Weyl expansion contain both homogeneous and inhomogeneous components. The connection between the Whittaker and Weyl expansions is discussed. A list of relevant spherically symmetric Fourier transforms is given.
Asymptotically Matched Layer (AML) for transient wave propagation in a moving frame of reference
DEFF Research Database (Denmark)
Madsen, Stine Skov; Krenk, Steen
2017-01-01
The paper presents an Asymptotically Matched Layer (AML) formulation in a moving frame of reference for transient dynamic response of a multi-layer 2D half-space. A displacement based finite element formulation of the convected domain problem is presented together with the AML formulation in which...... the original convolution integrals are represented via two auxiliary displacement-like state-space variables. A parametric study of the AML parameters is conducted for optimizing the absorbing properties. The performance is demonstrated on a single- and a two-layered half-space for various velocities...
Constructing and constraining wave functions for identical quantum particles
Sebens, Charles T.
2016-11-01
I address the problem of explaining why wave functions for identical particles must be either symmetric or antisymmetric (the symmetry dichotomy) within two interpretations of quantum mechanics which include particles following definite trajectories in addition to, or in lieu of, the wave function: Bohmian mechanics and Newtonian quantum mechanics (a.k.a. many interacting worlds). In both cases I argue that, if the interpretation is formulated properly, the symmetry dichotomy can be derived and need not be postulated.
Wave-function model for the CP violation in mesons.
Saberi Fathi, S M; Courbage, M; Durt, T
2017-10-01
In this paper, we propose a simple quantum model of the kaons decay providing an estimate of the CP symmetry violation parameter. We use the two-level Friedrich's Hamiltonian model to obtain a good quantitative agreement with the experimental estimate of the violation parameter for neutral kaons. A temporal wave-function approach, based on an analogy with spatial wave-functions, plays a crucial role in our model.
Wave function mapping conditions in Open Quantum Dots structures
Mendoza, M.; Schulz, P. A.
2003-01-01
We discuss the minimal conditions for wave function spectroscopy, in which resonant tunneling is the measurement tool. Two systems are addressed: resonant tunneling diodes, as a toy model, and open quantum dots. The toy model is used to analyze the crucial tunning between the necessary resolution in current-voltage characteristics and the breakdown of the wave functions probing potentials into a level splitting characteristic of double quantum wells. The present results establish a parameter ...
Wave-function model for the CP violation in mesons
Saberi Fathi, S. M.; Courbage, M.; Durt, T.
2017-10-01
In this paper, we propose a simple quantum model of the kaons decay providing an estimate of the CP symmetry violation parameter. We use the two-level Friedrich's Hamiltonian model to obtain a good quantitative agreement with the experimental estimate of the violation parameter for neutral kaons. A temporal wave-function approach, based on an analogy with spatial wave-functions, plays a crucial role in our model.
DEFF Research Database (Denmark)
Schmidt, Jakob Friis; Andersen, Thomas Rostgaard; Andersen, Lars Juel
2015-01-01
The aim of the study was to determine whether lifelong football training may improve cardiovascular function, physical fitness, and body composition. Our subjects were 17 male veteran football players (VPG; 68.1 ± 2.1 years) and 26 healthy age-matched untrained men who served as a control group (CG......, microvascular function, and a healthier body composition. Overall, VPG have better cardiovascular function compared with CG, which may reduce their cardiovascular morbidity and mortality....
Computer Network Defense Through Radial Wave Functions
Malloy, Ian
2016-01-01
The purpose of this research was to synthesize basic and fundamental findings in quantum computing, as applied to the attack and defense of conventional computer networks. The concept focuses on uses of radio waves as a shield for, and attack against traditional computers. A logic bomb is analogous to a landmine in a computer network, and if one was to implement it as non-trivial mitigation, it will aid computer network defense. As has been seen in kinetic warfare, the use of landmines has be...
Short-wave infrared barriode detectors using InGaAsSb absorption material lattice matched to GaSb
Energy Technology Data Exchange (ETDEWEB)
Craig, A. P.; Percy, B.; Marshall, A. R. J. [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom); Jain, M. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Wicks, G.; Hossain, K. [Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); Golding, T. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); McEwan, K.; Howle, C. [Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ (United Kingdom)
2015-05-18
Short-wave infrared barriode detectors were grown by molecular beam epitaxy. An absorption layer composition of In{sub 0.28}Ga{sub 0.72}As{sub 0.25}Sb{sub 0.75} allowed for lattice matching to GaSb and cut-off wavelengths of 2.9 μm at 250 K and 3.0 μm at room temperature. Arrhenius plots of the dark current density showed diffusion limited dark currents approaching those expected for optimized HgCdTe-based detectors. Specific detectivity figures of around 7×10{sup 10} Jones and 1×10{sup 10} Jones were calculated, for 240 K and room temperature, respectively. Significantly, these devices could support focal plane arrays working at higher operating temperatures.
Zhou, Hua-Cheng; Guo, Bao-Zhu
2017-08-01
In this paper, we consider boundary output feedback stabilization for a multi-dimensional wave equation with boundary control matched unknown nonlinear internal uncertainty and external disturbance. A new unknown input type extended state observer is proposed to recover both state and total disturbance which consists of internal uncertainty and external disturbance. A key feature of the proposed observer in this paper is that we do not use the high-gain to estimate the disturbance. By the active disturbance rejection control (ADRC) strategy, the total disturbance is compensated (canceled) in the feedback loop, which together with a collocated stabilizing controller without uncertainty, leads to an output feedback stabilizing feedback control. It is shown that the resulting closed-loop system is well-posed and asymptotically stable under weak assumption on internal uncertainty and external disturbance. The numerical experiments are carried out to show the effectiveness of the proposed scheme.
Rapidity resummation for B-meson wave functions
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Shen Yue-Long
2014-01-01
Full Text Available Transverse-momentum dependent (TMD hadronic wave functions develop light-cone divergences under QCD corrections, which are commonly regularized by the rapidity ζ of gauge vector defining the non-light-like Wilson lines. The yielding rapidity logarithms from infrared enhancement need to be resummed for both hadronic wave functions and short-distance functions, to achieve scheme-independent calculations of physical quantities. We briefly review the recent progress on the rapidity resummation for B-meson wave functions which are the key ingredients of TMD factorization formulae for radiative-leptonic, semi-leptonic and non-leptonic B-meson decays. The crucial observation is that rapidity resummation induces a strong suppression of B-meson wave functions at small light-quark momentum, strengthening the applicability of TMD factorization in exclusive B-meson decays. The phenomenological consequence of rapidity-resummation improved B-meson wave functions is further discussed in the context of B → π transition form factors at large hadronic recoil.
Functional reentrant waves propagate outwardly in cardiac tissue
Energy Technology Data Exchange (ETDEWEB)
Gong Yunfan [Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York, NY 10021 (United States)]. E-mail: yug2002@med.cornell.edu; Christini, David J. [Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York, NY 10021 (United States) and Department of Physiology and Biophysics, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021 (United States)]. E-mail: dchristi@med.cornell.edu
2004-10-18
The dynamical nature of cardiac arrhythmias has been investigated for decades by researchers from a wide range of disciplines. One long-standing unsettled issue involves whether the mechanism of functional reentry should be described by the 'leading-circle' hypothesis or the 'spiral-wave' hypothesis, which rely on inward and outward wave propagation, respectively. To address this issue, we investigated two-dimensional FitzHugh-Nagumo type models and found that inwardly propagating waves could occur in the spontaneous oscillatory mode, but not the excitable mode. However, such spontaneous oscillatory behavior is characterized by small-amplitude, sinusoidal oscillations that are fundamentally different from the stimulus-driven, excitable behavior of cardiac myocytes. This finding suggests that inward wave propagation, which is posited by the leading-circle hypothesis for the purpose of maintaining functional reentry, is unlikely to occur in cardiac tissue.
Microlocal limits of plane waves and Eisenstein functions
Dyatlov, Semyon; Guillarmou, Colin
2012-01-01
78 pages; We study microlocal limits of plane waves on noncompact Riemannian manifolds $(M,g)$ which are either Euclidean or asymptotically hyperbolic with curvature $-1$ near infinity. The plane waves $E(z,\\xi)$ are functions on $M$ parametrized by the square root of energy $z$ and the direction of the wave, $\\xi$, interpreted as a point at infinity. If the trapped set $K$ for the geodesic flow has Liouville measure zero, we show that, as $z\\to +\\infty$, $E(z,\\xi)$ microlocally converges to ...
Sheng, Yun; Sun, Huabin; Wang, Jianyu; Gao, Fan; Wang, Junzhuan; Pan, Lijia; Pu, Lin; Zheng, Youdou; Shi, Yi
2013-01-18
A strategy of using structurally matched alumina insulation to produce lateral electrodes on semiconductor nanowires is presented. Nanowires in the architecture are structurally matched with alumina insulation using selective anodic oxidation. Lateral electrodes are fabricated by directly evaporating metallic atoms onto the opposite sides of the nanowires. The integrated architecture with lateral electrodes propels carriers to transport them across nanowires and is crucially beneficial to the injection/extraction in optoelectronics. The matched architecture and the insulating properties of the alumina layer are investigated experimentally. ZnO nanowires are functionalized into an ultraviolet photodiode as an example. The present strategy successfully implements an advantageous architecture and is significant in developing diverse semiconductor nanowires in optoelectronic applications.
Probing hadron wave functions in Lattice QCD
Alexandrou, C; Tsapalis, A; Forcrand, Ph. de
2002-01-01
Gauge-invariant equal-time correlation functions are calculated in lattice QCD within the quenched approximation and with two dynamical quark species. These correlators provide information on the shape and multipole moments of the pion, the rho, the nucleon and the $\\Delta$.
A regularization of the Hartle–Hawking wave function
Directory of Open Access Journals (Sweden)
Nataliya N. Gorobey
2017-06-01
Full Text Available The paper puts forward a modification of the no-boundary Hartle–Hawking wave function in which, in the general case, the Euclidean functional integral can be described by an inhomogeneous universe. The regularization of this integral is achieved in arbitrary canonical calibration by abandoning integration over the lapse and shift functions. This makes it possible to ‘correct’ the sign of the Euclidean action corresponding to the scale factor of geometry. An additional time parameter associated with the canonical calibration condition then emerges. An additional condition for the stationary state of the wave function's phase after returning to the Lorentzian signature, serving as the quantum equivalent of the classical principle of the least action, was used to find this time parameter. We have substantiated the interpretation of the modified wave function as the amplitude of the universe's birth from ‘nothing’ with the additional parameter as the time of this process. A homogeneous model of the universe with a conformally invariant scalar field has been considered. In this case, two variants of the no-boundary wave function which are solutions of the Wheeler–DeWitt equation have been found.
Embedding beyond electrostatics-The role of wave function confinement.
Nåbo, Lina J; Olsen, Jógvan Magnus Haugaard; Holmgaard List, Nanna; Solanko, Lukasz M; Wüstner, Daniel; Kongsted, Jacob
2016-09-14
We study excited states of cholesterol in solution and show that, in this specific case, solute wave-function confinement is the main effect of the solvent. This is rationalized on the basis of the polarizable density embedding scheme, which in addition to polarizable embedding includes non-electrostatic repulsion that effectively confines the solute wave function to its cavity. We illustrate how the inclusion of non-electrostatic repulsion results in a successful identification of the intense π → π(∗) transition, which was not possible using an embedding method that only includes electrostatics. This underlines the importance of non-electrostatic repulsion in quantum-mechanical embedding-based methods.
On the interpretation of wave function overlaps in quantum dots
DEFF Research Database (Denmark)
Stobbe, Søren; Hvam, Jørn Märcher; Lodahl, Peter
2011-01-01
The spontaneous emission rate of excitons strongly confined in quantum dots (QDs) is proportional to the overlap integral of electron and hole envelope wave functions. A common and intuitive interpretation of this result is that the spontaneous emission rate is proportional to the probability...... that the electron and the hole are located at the same point or region in space, i.e., they must coincide spatially to recombine. Here, we show that this interpretation is not correct even loosely speaking. By general mathematical considerations we compare the envelope wave function overlap, the exchange overlap...
Towards an exact factorization of the molecular wave function
Parashar, Shubham; Sajeev, Y.; Ghosh, Swapan K.
2015-10-01
An exact single-product factorisation of the molecular wave function for the timedependent Schrödinger equation is investigated by using an ansatz involving a phase factor. By using the Frenkel variational method, we obtain the Schrödinger equations for the electronic and nuclear wave functions. The concept of a potential energy surface (PES) is retained by introducing a modified Hamiltonian as suggested earlier by Cederbaum. The parameter ω in the phase factor is chosen such that the equations of motion retain the physically appealing Born- Oppenheimer-like form, and is therefore unique.
Local spin: A treatment beyond single determinant wave functions
Alcoba, Diego R.; Lain, Luis; Torre, Alicia; Bochicchio, Roberto C.
2009-02-01
This Letter describes a partitioning of the expectation value of an N-electron system (molecule, ion, radical, etc.) into one- and two-center contributions. The proposal is valid for both independent and correlated particle models of the wave function. Our procedure provides local spin results which are physically reasonable for closed and open shell systems. Numerical results of the electronic spin population analyses of selected systems in the Hilbert space of atomic orbitals, arising from both single determinant wave functions and multideterminantal ones are analyzed and compared.
Period functions for Maass wave forms and cohomology
Bruggeman, R; Zagier, D; Bruggeman, R W; Zagier, D
2015-01-01
The authors construct explicit isomorphisms between spaces of Maass wave forms and cohomology groups for discrete cofinite groups \\Gamma\\subset\\mathrm{PSL}_2({\\mathbb{R}}). In the case that \\Gamma is the modular group \\mathrm{PSL}_2({\\mathbb{Z}}) this gives a cohomological framework for the results in Period functions for Maass wave forms. I, of J. Lewis and D. Zagier in Ann. Math. 153 (2001), 191-258, where a bijection was given between cuspidal Maass forms and period functions. The authors introduce the concepts of mixed parabolic cohomology group and semi-analytic vectors in principal serie
Directory of Open Access Journals (Sweden)
Ho-Ming Su
Full Text Available The P wave parameters measured by 12-lead electrocardiogram (ECG are commonly used as noninvasive tools to assess for left atrial enlargement. There are limited studies to evaluate whether P wave parameters are independently associated with decline in renal function. Accordingly, the aim of this study is to assess whether P wave parameters are independently associated with progression to renal end point of ≥25% decline in estimated glomerular filtration rate (eGFR. This longitudinal study included 166 patients. The renal end point was defined as ≥25% decline in eGFR. We measured two ECG P wave parameters corrected by heart rate, i.e. corrected P wave dispersion (PWdisperC and corrected P wave maximum duration (PWdurMaxC. Heart function and structure were measured from echocardiography. Clinical data, P wave parameters, and echocardiographic measurements were compared and analyzed. Forty-three patients (25.9% reached renal end point. Kaplan-Meier curves for renal end point-free survival showed PWdisperC > median (63.0 ms (log-rank P = 0.004 and PWdurMaxC > median (117.9 ms (log-rank P<0.001 were associated with progression to renal end point. Multivariate forward Cox-regression analysis identified increased PWdisperC (hazard ratio [HR], 1.024; P = 0.001 and PWdurMaxC (HR, 1.029; P = 0.001 were independently associated with progression to renal end point. Our results demonstrate that increased PWdisperC and PWdurMaxC were independently associated with progression to renal end point. Screening patients by means of PWdisperC and PWdurMaxC on 12 lead ECG may help identify a high risk group of rapid renal function decline.
Singh, Nagendra Pratap; Srivastava, Rajeev
2016-06-01
Retinal blood vessel segmentation is a prominent task for the diagnosis of various retinal pathology such as hypertension, diabetes, glaucoma, etc. In this paper, a novel matched filter approach with the Gumbel probability distribution function as its kernel is introduced to improve the performance of retinal blood vessel segmentation. Before applying the proposed matched filter, the input retinal images are pre-processed. During pre-processing stage principal component analysis (PCA) based gray scale conversion followed by contrast limited adaptive histogram equalization (CLAHE) are applied for better enhancement of retinal image. After that an exhaustive experiments have been conducted for selecting the appropriate value of parameters to design a new matched filter. The post-processing steps after applying the proposed matched filter include the entropy based optimal thresholding and length filtering to obtain the segmented image. For evaluating the performance of proposed approach, the quantitative performance measures, an average accuracy, average true positive rate (ATPR), and average false positive rate (AFPR) are calculated. The respective values of the quantitative performance measures are 0.9522, 0.7594, 0.0292 for DRIVE data set and 0.9270, 0.7939, 0.0624 for STARE data set. To justify the effectiveness of proposed approach, receiver operating characteristic (ROC) curve is plotted and the average area under the curve (AUC) is calculated. The average AUC for DRIVE and STARE data sets are 0.9287 and 0.9140 respectively. The obtained experimental results confirm that the proposed approach performance better with respect to other prominent Gaussian distribution function and Cauchy PDF based matched filter approaches. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Effects of 22 weeks of training on functional markers and match performance of young soccer players
Directory of Open Access Journals (Sweden)
Rodrigo Leal de Queiroz Thomaz de Aquino
2016-06-01
Full Text Available Abstract The aim of this study was to verify the effects of 22 weeks of training on functional markers and match performance through the use of earned points in competition. Twenty male soccer players were submitted to the same group of tests in four moments of the periodization: before the preparatory stage (T0; after the preparatory stage (T1; after the competitive stage I (T2; after the competitive stage II (T3. The functional markers were measured using the vertical and horizontal jump, T-40; Shuttle Run Test and RAST. The match performance was obtained by earned points in competition. An increase were found for all the variables analyzed for functional markers when T0 was compared with T3. In relation to the match performance, the team obtained 83.33% success in competitive stages. It is possible to conclude that training plan was efficient to improve technical-tactical skills and physical fitness of the studied athletes.
Frequency-domain Green's functions for radar waves in heterogeneous 2.5D media
Ellefsen, K.J.; Croize, D.; Mazzella, A.T.; McKenna, J.R.
2009-01-01
Green's functions for radar waves propagating in heterogeneous 2.5D media might be calculated in the frequency domain using a hybrid method. The model is defined in the Cartesian coordinate system, and its electromagnetic properties might vary in the x- and z-directions, but not in the y-direction. Wave propagation in the x- and z-directions is simulated with the finite-difference method, and wave propagation in the y-direction is simulated with an analytic function. The absorbing boundaries on the finite-difference grid are perfectly matched layers that have been modified to make them compatible with the hybrid method. The accuracy of these numerical Greens functions is assessed by comparing them with independently calculated Green's functions. For a homogeneous model, the magnitude errors range from -4.16% through 0.44%, and the phase errors range from -0.06% through 4.86%. For a layered model, the magnitude errors range from -2.60% through 2.06%, and the phase errors range from -0.49% through 2.73%. These numerical Green's functions might be used for forward modeling and full waveform inversion. ?? 2009 Society of Exploration Geophysicists. All rights reserved.
Quantum probability from a geometrical interpretation of a wave function
Sugiyama, K.
1999-01-01
The probabilistic prediction of quantum theory is mystery. I solved the mystery by a geometrical interpretation of a wave function. This suggests the unification between quantum theory and the theory of relativity. This suggests Many-Worlds Interpretation is true, too.
Explicitly correlated wave function for a boron atom
Puchalski, Mariusz; Pachucki, Krzysztof
2015-01-01
We present results of high-precision calculations for a boron atom's properties using wave functions expanded in the explicitly correlated Gaussian basis. We demonstrate that the well-optimized 8192 basis functions enable a determination of energy levels, ionization potential, and fine and hyperfine splittings in atomic transitions with nearly parts per million precision. The results open a window to a spectroscopic determination of nuclear properties of boron including the charge radius of the proton halo in the $^8$B nucleus.
Projector Quantum Monte Carlo Method for Nonlinear Wave Functions
Schwarz, Lauretta R.; Alavi, A.; Booth, George H.
2017-04-01
We reformulate the projected imaginary-time evolution of the full configuration interaction quantum Monte Carlo method in terms of a Lagrangian minimization. This naturally leads to the admission of polynomial complex wave function parametrizations, circumventing the exponential scaling of the approach. While previously these functions have traditionally inhabited the domain of variational Monte Carlo approaches, we consider recent developments for the identification of deep-learning neural networks to optimize this Lagrangian, which can be written as a modification of the propagator for the wave function dynamics. We demonstrate this approach with a form of tensor network state, and use it to find solutions to the strongly correlated Hubbard model, as well as its application to a fully periodic ab initio graphene sheet. The number of variables which can be simultaneously optimized greatly exceeds alternative formulations of variational Monte Carlo methods, allowing for systematic improvability of the wave function flexibility towards exactness for a number of different forms, while blurring the line between traditional variational and projector quantum Monte Carlo approaches.
Horizon wave-function and the quantum cosmic censorship
Casadio, Roberto; Micu, Octavian; Stojkovic, Dejan
2015-07-01
We investigate the Cosmic Censorship Conjecture by means of the horizon wave-function (HWF) formalism. We consider a charged massive particle whose quantum mechanical state is represented by a spherically symmetric Gaussian wave-function, and restrict our attention to the superextremal case (with charge-to-mass ratio α > 1), which is the prototype of a naked singularity in the classical theory. We find that one can still obtain a normalisable HWF for α2 2, and the uncertainty in the location of the horizon blows up at α2 = 2, signalling that such an object is no more well-defined. This perhaps implies that a quantum Cosmic Censorship might be conjectured by stating that no black holes with charge-to-mass ratio greater than a critical value (of the order of √{ 2}) can exist.
Horizon wave-function and the quantum cosmic censorship
Directory of Open Access Journals (Sweden)
Roberto Casadio
2015-07-01
Full Text Available We investigate the Cosmic Censorship Conjecture by means of the horizon wave-function (HWF formalism. We consider a charged massive particle whose quantum mechanical state is represented by a spherically symmetric Gaussian wave-function, and restrict our attention to the superextremal case (with charge-to-mass ratio α>1, which is the prototype of a naked singularity in the classical theory. We find that one can still obtain a normalisable HWF for α22, and the uncertainty in the location of the horizon blows up at α2=2, signalling that such an object is no more well-defined. This perhaps implies that a quantum Cosmic Censorship might be conjectured by stating that no black holes with charge-to-mass ratio greater than a critical value (of the order of 2 can exist.
Many-body lattice wave functions from conformal blocks
Montes, Sebastián; Rodríguez-Laguna, Javier; Tu, Hong-Hao; Sierra, Germán
2017-02-01
We introduce a general framework to construct many-body lattice wave functions starting from the conformal blocks (CBs) of rational conformal field theories (RCFTs). We discuss the different ways of encoding the physical degrees of freedom of the lattice system using both the internal symmetries of the theory and the fusion channels of the CBs. We illustrate this construction both by revisiting the known Haldane-Shastry model and by providing a novel implementation for the Ising RCFT. In the latter case, we find a connection to the Ising transverse field (ITF) spin chain via the Kramers-Wannier duality and the Temperley-Lieb-Jones algebra. We also find evidence that the ground state of the finite-size critical ITF Hamiltonian corresponds exactly to the wave function obtained from CBs of spin fields.
Configuration interaction wave functions: A seniority number approach
Energy Technology Data Exchange (ETDEWEB)
Alcoba, Diego R. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Física de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Torre, Alicia; Lain, Luis, E-mail: qfplapel@lg.ehu.es [Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, E-48080 Bilbao (Spain); Massaccesi, Gustavo E. [Departamento de Ciencias Exactas, Ciclo Básico Común, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Oña, Ofelia B. [Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Universidad Nacional de La Plata, CCT La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Diag. 113 y 64 (S/N), Sucursal 4, CC 16, 1900 La Plata (Argentina)
2014-06-21
This work deals with the configuration interaction method when an N-electron Hamiltonian is projected on Slater determinants which are classified according to their seniority number values. We study the spin features of the wave functions and the size of the matrices required to formulate states of any spin symmetry within this treatment. Correlation energies associated with the wave functions arising from the seniority-based configuration interaction procedure are determined for three types of molecular orbital basis: canonical molecular orbitals, natural orbitals, and the orbitals resulting from minimizing the expectation value of the N-electron seniority number operator. The performance of these bases is analyzed by means of numerical results obtained from selected N-electron systems of several spin symmetries. The comparison of the results highlights the efficiency of the molecular orbital basis which minimizes the mean value of the seniority number for a state, yielding energy values closer to those provided by the full configuration interaction procedure.
Nielsen, Henrik Bjørn; Mundy, John; Willenbrock, Hanni
2007-08-01
The systematic comparison of transcriptional responses of organisms is a powerful tool in functional genomics. For example, mutants may be characterized by comparing their transcript profiles to those obtained in other experiments querying the effects on gene expression of many experimental factors including treatments, mutations and pathogen infections. Similarly, drugs may be discovered by the relationship between the transcript profiles effectuated or impacted by a candidate drug and by the target disease. The integration of such data enables systems biology to predict the interplay between experimental factors affecting a biological system. Unfortunately, direct comparisons of gene expression profiles obtained in independent, publicly available microarray experiments are typically compromised by substantial, experiment-specific biases. Here we suggest a novel yet conceptually simple approach for deriving 'Functional Association(s) by Response Overlap' (FARO) between microarray gene expression studies. The transcriptional response is defined by the set of differentially expressed genes independent from the magnitude or direction of the change. This approach overcomes the limited comparability between studies that is typical for methods that rely on correlation in gene expression. We apply FARO to a compendium of 242 diverse Arabidopsis microarray experimental factors, including phyto-hormones, stresses and pathogens, growth conditions/stages, tissue types and mutants. We also use FARO to confirm and further delineate the functions of Arabidopsis MAP kinase 4 in disease and stress responses. Furthermore, we find that a large, well-defined set of genes responds in opposing directions to different stress conditions and predict the effects of different stress combinations. This demonstrates the usefulness of our approach for exploiting public microarray data to derive biologically meaningful associations between experimental factors. Finally, our results indicate
Joint resummation for pion wave function and pion transition form factor
Energy Technology Data Exchange (ETDEWEB)
Li, Hsiang-nan [Institute of Physics, Academia Sinica,Academia Rd., Taipei, Taiwan 115 (China); Department of Physics, National Cheng-Kung University,University Rd., Tainan, Taiwan 701 (China); Department of Physics, National Tsing-Hua University,Kuang-Fu Rd., Hsinchu, Taiwan 300 (China); Shen, Yue-Long [College of Information Science and Engineering, Ocean University of China,Songling Rd, Qingdao, Shandong 266100 (China); Wang, Yu-Ming [Institut für Theoretische Teilchenphysik und Kosmologie RWTH Aachen,Physikzentrum Otto-Blumenthal-Straße, D-52056 Aachen (Germany); Physik Department T31, Technische Universität München,James-Franck-Straße, D-85748 Garching (Germany)
2014-01-03
We construct an evolution equation for the pion wave function in the k{sub T} factorization formalism, whose solution sums the mixed logarithm ln xln k{sub T} to all orders, with x (k{sub T}) being a parton momentum fraction (transverse momentum). This joint resummation induces strong suppression of the pion wave function in the small x and large b regions, b being the impact parameter conjugate to k{sub T}, and improves the applicability of perturbative QCD to hard exclusive processes. The above effect is similar to those from the conventional threshold resummation for the double logarithm ln{sup 2} x and the conventional k{sub T} resummation for ln{sup 2} k{sub T}. Combining the evolution equation for the hard kernel, we are able to organize all large logarithms in the γ{sup ∗}π{sup 0}→γ scattering, and to establish a scheme-independent k{sub T} factorization formula. It will be shown that the significance of next-to-leading-order contributions and saturation behaviors of this process at high energy differ from those under the conventional resummations. It implies that QCD logarithmic corrections to a process must be handled appropriately, before its data are used to extract a hadron wave function. Our predictions for the involved pion transition form factor, derived under the joint resummation and the input of a non-asymptotic pion wave function with the second Gegenbauer moment a{sub 2}=0.05, match reasonably well the CLEO, BaBar, and Belle data.
DEFF Research Database (Denmark)
Nielsen, Henrik Bjørn; Mundy, J.; Willenbrock, Hanni
2007-01-01
including treatments, mutations and pathogen infections. Similarly, drugs may be discovered by the relationship between the transcript profiles effectuated or impacted by a candidate drug and by the target disease. The integration of such data enables systems biology to predict the interplay between...... experimental factors affecting a biological system. Unfortunately, direct comparisons of gene expression profiles obtained in independent, publicly available microarray experiments are typically compromised by substantial, experiment-specific biases. Here we suggest a novel yet conceptually simple approach...... to confirm and further delineate the functions of Arabidopsis MAP kinase 4 in disease and stress responses. Furthermore, we find that a large, well-defined set of genes responds in opposing directions to different stress conditions and predict the effects of different stress combinations. This demonstrates...
Energy Technology Data Exchange (ETDEWEB)
Xia, Donghui [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Huang, Mei [Southwestern Institute of Physics, 610041 Chengdu (China); Wang, Zhijiang, E-mail: wangzj@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhang, Feng [Southwestern Institute of Physics, 610041 Chengdu (China); Zhuang, Ge [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)
2016-10-15
Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.
Directory of Open Access Journals (Sweden)
Feng Jin
Full Text Available Feature detection and matching are crucial for robust and reliable image registration. Although many methods have been developed, they commonly focus on only one class of image features. The methods that combine two or more classes of features are still novel and significant. In this work, methods for feature detection and matching are proposed. A Mexican hat function-based operator is used for image feature detection, including the local area detection and the feature point detection. For the local area detection, we use the Mexican hat operator for image filtering, and then the zero-crossing points are extracted and merged into the area borders. For the feature point detection, the Mexican hat operator is performed in scale space to get the key points. After the feature detection, an image registration is achieved by using the two classes of image features. The feature points are grouped according to a standardized region that contains correspondence to the local area, precise registration is achieved eventually by the grouped points. An image transformation matrix is estimated by the feature points in a region and then the best one is chosen through competition of a set of the transformation matrices. This strategy has been named the Grouped Sample Consensus (GCS. The GCS has also ability for removing the outliers effectively. The experimental results show that the proposed algorithm has high registration accuracy and small computational volume.
Orbital dependent functionals: An atom projector augmented wave method implementation
Xu, Xiao
This thesis explores the formulation and numerical implementation of orbital dependent exchange-correlation functionals within electronic structure calculations. These orbital-dependent exchange-correlation functionals have recently received renewed attention as a means to improve the physical representation of electron interactions within electronic structure calculations. In particular, electron self-interaction terms can be avoided. In this thesis, an orbital-dependent functional is considered in the context of Hartree-Fock (HF) theory as well as the Optimized Effective Potential (OEP) method and the approximate OEP method developed by Krieger, Li, and Iafrate, known as the KLI approximation. In this thesis, the Fock exchange term is used as a simple well-defined example of an orbital-dependent functional. The Projected Augmented Wave (PAW) method developed by P. E. Blochl has proven to be accurate and efficient for electronic structure calculations for local and semi-local functions because of its accurate evaluation of interaction integrals by controlling multiple moments. We have extended the PAW method to treat orbital-dependent functionals in Hartree-Fock theory and the Optimized Effective Potential method, particularly in the KLI approximation. In the course of study we develop a frozen-core orbital approximation that accurately treats the core electron contributions for above three methods. The main part of the thesis focuses on the treatment of spherical atoms. We have investigated the behavior of PAW-Hartree Fock and PAW-KLI basis, projector, and pseudopotential functions for several elements throughout the periodic table. We have also extended the formalism to the treatment of solids in a plane wave basis and implemented PWPAW-KLI code, which will appear in future publications.
Tiberi, Gianluigi; Fontana, Nunzia; Monorchio, Agostino; Stara, Riccardo; Retico, Alessandra; Tosetti, Michela
2015-12-01
A procedure for evaluating radio-frequency electromagnetic fields in anatomical human models for any matching and coupling conditions is introduced. The procedure resorts to the extraction of basis functions: such basis functions, which represent the fields produced by each individual port without any residual coupling, are derived through an algebraic procedure which uses the S parameter matrix and the fields calculated in one (only) full-wave simulation. The basis functions are then used as building-blocks for calculating the fields for any other S parameter matrix. The proposed approach can be used both for volume coil driven in quadrature and for parallel transmission configuration. Copyright © 2015 Elsevier Inc. All rights reserved.
On irregular singularity wave functions and superconformal indices
Buican, Matthew; Nishinaka, Takahiro
2017-09-01
We generalize, in a manifestly Weyl-invariant way, our previous expressions for irregular singularity wave functions in two-dimensional SU(2) q-deformed Yang-Mills theory to SU( N). As an application, we give closed-form expressions for the Schur indices of all ( A N - 1 , A N ( n - 1)-1) Argyres-Douglas (AD) superconformal field theories (SCFTs), thus completing the computation of these quantities for the ( A N , A M ) SCFTs. With minimal effort, our wave functions also give new Schur indices of various infinite sets of "Type IV" AD theories. We explore the discrete symmetries of these indices and also show how highly intricate renormalization group (RG) flows from isolated theories and conformal manifolds in the ultraviolet to isolated theories and (products of) conformal manifolds in the infrared are encoded in these indices. We compare our flows with dimensionally reduced flows via a simple "monopole vev RG" formalism. Finally, since our expressions are given in terms of concise Lie algebra data, we speculate on extensions of our results that might be useful for probing the existence of hypothetical SCFTs based on other Lie algebras. We conclude with a discussion of some open problems.
Extracting Supersymmetry-Breaking Effects from Wave-Function Renormalization
Giudice, Gian Francesco
1998-01-01
We show that in theories in which supersymmetry breaking is communicated by renormalizable perturbative interactions, it is possible to extract the soft terms for the observable fields from wave-function renormalization. Therefore all the information about soft terms can be obtained from anomalous dimensions and beta functions, with no need to further compute any Feynman diagram. This method greatly simplifies calculations which are rather involved if performed in terms of component fields. For illustrative purposes we reproduce known results of theories with gauge-mediated supersymmetry breaking. We then use our method to obtain new results of phenomenological importance. We calculate the next-to-leading correction to the Higgs mass parameters, the two-loop soft terms induced by messenger-matter superpotential couplings, and the soft terms generated by messengers belonging to vector supermultiplets.
Monte Carlo variational study of Be: A survey of correlated wave functions
Moskowitz, Jules W.; Schmidt, K. E.; Lee, M. A.; Kalos, M. H.
1982-01-01
Using the Metropolis Monte Carlo integration technique, we calculate upper bounds to the correlation energy of a Be atom for a variety of wave functions. With this method, it is simple to treat unconventional wave functions, including those which depend on the interelectronic distance rij. We obtain about 40% of the correlation energy by using only a simple two-parameter Jastrow function of rij with a single Slater determinant of Hartree-Fock orbitals. A four configuration wave function with this Jastrow function yields 87% of the correlation energy. Several wave functions derived from nonvariational methods are shown to give no correlation energy when used in a strictly variational computation.
Meta-Analyses of Ethnic Match as a Predictor of Dropout, Utilization, and Level of Functioning.
Maramba, Gloria Gia; Hall, Gordon C. Nagayama
2002-01-01
Meta-analyses were performed on seven studies of ethnic match and psychotherapy. Results reveal a small dropout and utilization effect sizes, indicating that ethnic match is not a significant clinical predictor of decreasing dropout after the first session or increasing number of sessions attended. (Contains references and tables.) (GCP)
Timme, Marc; van Bussel, Frank; Fliegner, Denny; Stolzenberg, Sebastian
2009-02-01
Counting problems, determining the number of possible states of a large system under certain constraints, play an important role in many areas of science. They naturally arise for complex disordered systems in physics and chemistry, in mathematical graph theory, and in computer science. Counting problems, however, are among the hardest problems to access computationally. Here, we suggest a novel method to access a benchmark counting problem, finding chromatic polynomials of graphs. We develop a vertex-oriented symbolic pattern matching algorithm that exploits the equivalence between the chromatic polynomial and the zero-temperature partition function of the Potts antiferromagnet on the same graph. Implementing this bottom-up algorithm using appropriate computer algebra, the new method outperforms standard top-down methods by several orders of magnitude, already for moderately sized graphs. As a first application, we compute chromatic polynomials of samples of the simple cubic lattice, for the first time computationally accessing three-dimensional lattices of physical relevance. The method offers straightforward generalizations to several other counting problems.
Energy Technology Data Exchange (ETDEWEB)
Timme, Marc; Van Bussel, Frank; Fliegner, Denny [Max Planck Institute for Dynamics and Self-Organization, Bunsenstrasse 10, 37073 Goettingen (Germany); Stolzenberg, Sebastian [Department of Physics, Cornell University, 109 Clark Hall, Ithaca, NY 14853-2501 (United States)], E-mail: timme@nld.ds.mpg.de
2009-02-15
Counting problems, determining the number of possible states of a large system under certain constraints, play an important role in many areas of science. They naturally arise for complex disordered systems in physics and chemistry, in mathematical graph theory, and in computer science. Counting problems, however, are among the hardest problems to access computationally. Here, we suggest a novel method to access a benchmark counting problem, finding chromatic polynomials of graphs. We develop a vertex-oriented symbolic pattern matching algorithm that exploits the equivalence between the chromatic polynomial and the zero-temperature partition function of the Potts antiferromagnet on the same graph. Implementing this bottom-up algorithm using appropriate computer algebra, the new method outperforms standard top-down methods by several orders of magnitude, already for moderately sized graphs. As a first application, we compute chromatic polynomials of samples of the simple cubic lattice, for the first time computationally accessing three-dimensional lattices of physical relevance. The method offers straightforward generalizations to several other counting problems.
Musin, Roman R; Xing, Qirong; Li, Yanfeng; Hu, Minglie; Chai, Lu; Wang, Qingyue; Mikhailova, Yuliya M; Nazarov, Maksim M; Shkurinov, Alexander P; Zheltikov, Aleksei M
2008-02-01
The theory of guided waves in metal-dielectric planar multilayer structures is applied to reduce the loss and maximize optical nonlinearity for efficient terahertz-field generation in a surface electromagnetic wave by femtosecond laser pulses confined in a (chi)((2)) nonlinear planar waveguide. For typical parameters of thin-film polymer waveguides and metal-dielectric interfaces, the optimal size of the (chi)((2)) waveguide core providing the maximum efficiency of terahertz plasmon-field generation is shown to be less than the wavelength of the optical pump field.
Chi-Durán, Rodrigo; Comte, Diana; Díaz, Marcos; Silva, Jorge F.
2017-09-01
In this work, new strategies for automatic identification of P- and S-wave arrival times from digital recorded local seismograms are proposed and analyzed. The database of arrival times previously identified by a human reader was compared with automatic identification techniques based on the Fourier transformation in reduced time (spectrograms), fractal analysis, and the basic matching pursuit algorithm. The first two techniques were used to identify the P-wave arrival times, while the third was used for the identification of the S-wave. For validation, the results were compared with the short-time average over long-time average (STA/LTA) of Rietbrock et al., Geophys Res Lett 39(8), (2012) for the database of aftershocks of the 2010 Maule M w = 8.8 earthquake. The identifiers proposed in this work exhibit good results that outperform the STA/LTA identifier in many scenarios. The average difference from the reference picks (times obtained by the human reader) in P- and S-wave arrival times is ˜ 1 s.
Multi-Determinant Wave-functions in Quantum Monte Carlo
Morales, M A; Clark, B K; Kim, J; Scuseria, G; 10.1021/ct3003404
2013-01-01
Quantum Monte Carlo (QMC) methods have received considerable attention over the last decades due to their great promise for providing a direct solution to the many-body Schrodinger equation in electronic systems. Thanks to their low scaling with number of particles, QMC methods present a compelling competitive alternative for the accurate study of large molecular systems and solid state calculations. In spite of such promise, the method has not permeated the quantum chemistry community broadly, mainly because of the fixed-node error, which can be large and whose control is difficult. In this Perspective, we present a systematic application of large scale multi-determinant expansions in QMC, and report on its impressive performance with first row dimers and the 55 molecules of the G1 test set. We demonstrate the potential of this strategy for systematically reducing the fixed-node error in the wave function and for achieving chemical accuracy in energy predictions. When compared to traditional quantum chemistr...
Precise wave-function engineering with magnetic resonance
Wigley, P. B.; Starkey, L. M.; Szigeti, S. S.; Jasperse, M.; Hope, J. J.; Turner, L. D.; Anderson, R. P.
2017-07-01
Controlling quantum fluids at their fundamental length scale will yield superlative quantum simulators, precision sensors, and spintronic devices. This scale is typically below the optical diffraction limit, precluding precise wave-function engineering using optical potentials alone. We present a protocol to rapidly control the phase and density of a quantum fluid down to the healing length scale using strong time-dependent coupling between internal states of the fluid in a magnetic field gradient. We demonstrate this protocol by simulating the creation of a single stationary soliton and double soliton states in a Bose-Einstein condensate with control over the individual soliton positions and trajectories, using experimentally feasible parameters. Such states are yet to be realized experimentally, and are a path towards engineering soliton gases and exotic topological excitations.
The wave function essays on the metaphysics of quantum mechanics
Albert, David Z
2013-01-01
This is a new volume of original essays on the metaphysics of quantum mechanics. The essays address questions such as: What fundamental metaphysics is best motivated by quantum mechanics? What is the ontological status of the wave function? Does quantum mechanics support the existence of any other fundamental entities, e.g. particles? What is the nature of the fundamental space (or space-time manifold) of quantum mechanics? What is the relationship between the fundamental ontology of quantum mechanics and ordinary, macroscopic objects like tables, chairs, and persons? This collection includes a comprehensive introduction with a history of quantum mechanics and the debate over its metaphysical interpretation focusing especially on the main realist alternatives.
Revisiting glueball wave functions at zero and finite temperature
Loan, Mushtaq
2008-01-01
We study the sizes and thermal properties of glueballs in a three dimensional compact Abelian gauge model on improved lattice. We predict the radii of $\\sim 0.60$ and $\\sim 1.12$ in the units of string tension, or $\\sim 0.28$ and $\\sim 0.52$ fm, for the scalar and tensor glueballs, respectively. We perform a well controlled extrapolation of the radii to the continuum limit and observe that our results agree with the predicted values. Using Monte Carlo simulations, we extract the pole-mass of the lowest scalar and tensor glueballs from the temporal correlators at finite temperature. We see a clear evidence of the deconfined phase, and the transition appears to be similar to that of the two-dimensional XY model as expected from universality arguments. Our results show no significant changes in the glueball wave functions and masses in the deconfined phase.
Electron Correlation from the Adiabatic Connection for Multireference Wave Functions
Pernal, Katarzyna
2018-01-01
An adiabatic connection (AC) formula for the electron correlation energy is derived for a broad class of multireference wave functions. The AC expression recovers dynamic correlation energy and assures a balanced treatment of the correlation energy. Coupling the AC formalism with the extended random phase approximation allows one to find the correlation energy only from reference one- and two-electron reduced density matrices. If the generalized valence bond perfect pairing model is employed a simple closed-form expression for the approximate AC formula is obtained. This results in the overall M5 scaling of the computation cost making the method one of the most efficient multireference approaches accounting for dynamic electron correlation also for the strongly correlated systems.
Comparative study on spreading function for directional wave spectra
Digital Repository Service at National Institute of Oceanography (India)
Bhat, S.S.; Anand, N.M.; Nayak, B.U.
The planning and design of all coastal and offshore installations call for an information on wave directionality. This can be accurately obtained through the knowledge of the directional wave spectrum which is commonly given as a product of one...
CSIR Research Space (South Africa)
Bogaers, Alfred EJ
2016-10-01
Full Text Available , transferring information across a non-matching interface presents itself as a nontrivial problem. RBF interpolation, which requires no global connectivity information, provides an elegant means by which to negate any geometric discrepancies along the interface...
Unitary networks from the exact renormalization of wave functionals
Fliss, Jackson R.; Leigh, Robert G.; Parrikar, Onkar
2017-06-01
The exact renormalization group (ERG) for O (N ) vector models (at large N ) on flat Euclidean space can be interpreted as the bulk dynamics corresponding to a holographically dual higher spin gauge theory on AdSd +1. This was established in the sense that at large N the generating functional of correlation functions of single-trace operators is reproduced by the on-shell action of the bulk higher spin theory, which is most simply presented in a first-order (phase space) formalism. In this paper, we extend the ERG formalism to the wave functionals of arbitrary states of the O (N ) vector model at the free fixed point. We find that the ERG flow of the ground state and a specific class of excited states is implemented by the action of unitary operators which can be chosen to be local. Consequently, the ERG equations provide a continuum notion of a tensor network. We compare this tensor network with the entanglement renormalization networks, MERA, and its continuum version, cMERA, which have appeared recently in holographic contexts. In particular, the ERG tensor network appears to share the general structure of cMERA but differs in important ways. We comment on possible holographic implications.
On the Galilean transformation of the few-electron wave functions
Frolov, Alexei M
2013-01-01
The Galilean transformations of the few-electron atomic wave functions are considered. We discuss the few-electron wave functions constructed in the model of independent electrons as well as the truly correlated (or highly accurate) wave functions. Results of our analysis are applied to determine the probability of formation of the negatively charged tritium/protium ions during the nuclear $(n,{}^{3}$He$;t,p)-$reaction of the helium-3 atoms with thermal/slow neutrons.
Energy Technology Data Exchange (ETDEWEB)
Ritboon, Atirach, E-mail: atirach.3.14@gmail.com [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand); Daengngam, Chalongrat, E-mail: chalongrat.d@psu.ac.th [Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand); Pengpan, Teparksorn, E-mail: teparksorn.p@psu.ac.th [Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand)
2016-08-15
Biakynicki-Birula introduced a photon wave function similar to the matter wave function that satisfies the Schrödinger equation. Its second quantization form can be applied to investigate nonlinear optics at nearly full quantum level. In this paper, we applied the photon wave function formalism to analyze both linear optical processes in the well-known Mach–Zehnder interferometer and nonlinear optical processes for sum-frequency generation in dispersive and lossless medium. Results by photon wave function formalism agree with the well-established Maxwell treatments and existing experimental verifications.
A 31.7-GHz high linearity millimeter-wave CMOS LNA using an ultra-wideband input matching technique
Geliang, Yang; Zhigong, Wang; Zhiqun, Li; Qin, Li; Zhu, Li; Faen, Liu
2012-12-01
A CMOS low-noise amplifier (LNA) operating at 31.7 GHz with a low input return loss (S11) and high linearity is proposed. The wideband input matching was achieved by employing a simple LC compounded network to generate more than one S11 dip below -10 dB level. The principle of the matching circuit is analyzed and the critical factors with significant effect on the input impedance (Zin) are determined. The relationship between the input impedance and the load configuration is explored in depth, which is seldom concentrated upon previously. In addition, the noise of the input stage is modeled using a cascading matrix instead of conventional noise theory. In this way Zin and the noise figure can be calculated using one uniform formula. The linearity analysis is also performed in this paper. Finally, an LNA was designed for demonstration purposes. The measurement results show that the proposed LNA achieves a maximum power gain of 9.7 dB and an input return loss of RF CMOS process and occupies an area of 755 × 670 μm2 including pads. The whole circuit dissipates a DC power of 24 mW from one 1.3-V supply.
Predicting soccer matches after unconscious and conscious thought as a function of expertise
Dijksterhuis, A.; Bos, M.W.; van der Leij, A.; van Baaren, R.B.
2009-01-01
In two experiments, we investigated the effects of expertise and mode of thought on the accuracy of people’s predictions. Both experts and nonexperts predicted the results of soccer matches after conscious thought, after unconscious thought, or immediately. In Experiment 1, experts who thought
Predicting Soccer Matches After Unconscious and Conscious Thought as a Function of Expertise
Dijksterhuis, A.J.; Bos, M.W.; Leij, A.R. van der; Baaren, Rickvan
2009-01-01
In two experiments, we investigated the effects of expertise and mode of thought on the accuracy of people's predictions. Both experts and nonexperts predicted the results of soccer matches after conscious thought, after unconscious thought, or immediately. In Experiment 1, experts who thought
Wapenaar, Kees
2017-06-01
A unified scalar wave equation is formulated, which covers three-dimensional (3D) acoustic waves, 2D horizontally-polarised shear waves, 2D transverse-electric EM waves, 2D transverse-magnetic EM waves, 3D quantum-mechanical waves and 2D flexural waves. The homogeneous Green's function of this wave equation is a combination of the causal Green's function and its time-reversal, such that their singularities at the source position cancel each other. A classical representation expresses this homogeneous Green's function as a closed boundary integral. This representation finds applications in holographic imaging, time-reversed wave propagation and Green's function retrieval by cross correlation. The main drawback of the classical representation in those applications is that it requires access to a closed boundary around the medium of interest, whereas in many practical situations the medium can be accessed from one side only. Therefore, a single-sided representation is derived for the homogeneous Green's function of the unified scalar wave equation. Like the classical representation, this single-sided representation fully accounts for multiple scattering. The single-sided representation has the same applications as the classical representation, but unlike the classical representation it is applicable in situations where the medium of interest is accessible from one side only.
Covariant nucleon wave function with S, D, and P-state components
Energy Technology Data Exchange (ETDEWEB)
Franz Gross, G. Ramalho, M. T. Pena
2012-05-01
Expressions for the nucleon wave functions in the covariant spectator theory (CST) are derived. The nucleon is described as a system with a off-mass-shell constituent quark, free to interact with an external probe, and two spectator constituent quarks on their mass shell. Integrating over the internal momentum of the on-mass-shell quark pair allows us to derive an effective nucleon wave function that can be written only in terms of the quark and diquark (quark-pair) variables. The derived nucleon wave function includes contributions from S, P and D-waves.
National Research Council Canada - National Science Library
Herrmann, Robert B; Julia, Jordi; Ammon, Charles J
2007-01-01
.... Receiver functions are primarily sensitive to shear-wave velocity contrast and vertical travel times and surface-wave dispersion measurements are sensitive to vertical shear-wave velocity averages...
National Research Council Canada - National Science Library
Julia, Jordi; Ammon, Charles J; Herrimann, Robert B
2006-01-01
.... Receiver functions are primarily sensitive to shear-wave velocity contrasts and vertical travel times and surface-wave dispersion measurements are sensitive to vertical shear-wave velocity averages...
Shock Wave Propagation in Functionally Graded Mineralized Tissue
Nelms, Matthew; Hodo, Wayne; Livi, Ken; Browning, Alyssa; Crawford, Bryan; Rajendran, A. M.
2017-06-01
In this investigation, the effects of shock wave propagation in bone-like biomineralized tissue was investigated. The Alligator gar (Atractosteus spatula) exoskeleton is comprised of many disparate scales that provide a biological analog for potential design of flexible protective material systems. The gar scale is identified as a two-phase, (1) hydroxyapatite mineral and (2) collagen protein, biological composite with two distinct layers where a stiff, ceramic-like ganoine overlays a soft, highly ductile ganoid bone. Previous experimentations has shown significant softening under compressive loading and an asymmetrical stress-strain response for analogous mineralized tissues. The structural features, porosity, and elastic modulus were determined from high-resolution scanning electron microscopy, 3D micro-tomography, and dynamic nanoindentation experiments to develop an idealized computational model for FE simulations. The numerical analysis employed Gurson's yield criterion to determine the influence of porosity and pressure on material strength. Functional gradation of elastic moduli and certain structural features, such as the sawtooth interface, are explicitly modeled to study the plate impact shock profile for a full 3-D analysis using ABAQUS finite element software.
Dynamical dissociation of quarkonia by wave function decoherence
Kajimoto, Shiori; Akamatsu, Yukinao; Asakawa, Masayuki; Rothkopf, Alexander
2018-01-01
We investigate the real-time evolution of quarkonium bound states in a quark-gluon plasma in one dimension using an improved QCD-based stochastic potential model. This model describes the quarkonium dynamics in terms of a Schrödinger equation with an in-medium potential and two noise terms encoding the residual interactions between the heavy quarks and the medium. The probabilities of bound states in a static medium and in a boost-invariantly expanding quark-gluon plasma are discussed. We draw two conclusions from our results: One is that the outcome of the stochastic potential model is qualitatively consistent with the experimental data in relativistic heavy-ion collisions. The other is that the noise plays an important role in order to describe quarkonium dynamics in medium; in particular, it causes decoherence of the quarkonium wave function. The effectiveness of decoherence is controlled by a new length scale lcorr. It represents the noise correlation length and its effect has not been included in existing phenomenological studies.
Directory of Open Access Journals (Sweden)
Banu Ünalmış Uzun
2017-06-01
Full Text Available Abstract We state the fractional Fourier transform and the continuous fractional wave packet transform as ways for analyzing persistent signals such as almost periodic functions and strong limit power signals. We construct frame decompositions for almost periodic functions using these two transforms. Also a norm equality of this signal is given using the continuous fractional wave packet transform.
Uzun, Banu Ünalmış
2017-01-01
We state the fractional Fourier transform and the continuous fractional wave packet transform as ways for analyzing persistent signals such as almost periodic functions and strong limit power signals. We construct frame decompositions for almost periodic functions using these two transforms. Also a norm equality of this signal is given using the continuous fractional wave packet transform.
Uzun, Banu ?nalm??
2017-01-01
We state the fractional Fourier transform and the continuous fractional wave packet transform as ways for analyzing persistent signals such as almost periodic functions and strong limit power signals. We construct frame decompositions for almost periodic functions using these two transforms. Also a norm equality of this signal is given using the continuous fractional wave packet transform.
Banu Ünalmış Uzun
2017-01-01
Abstract We state the fractional Fourier transform and the continuous fractional wave packet transform as ways for analyzing persistent signals such as almost periodic functions and strong limit power signals. We construct frame decompositions for almost periodic functions using these two transforms. Also a norm equality of this signal is given using the continuous fractional wave packet transform.
Directory of Open Access Journals (Sweden)
L. Sun
2007-10-01
Full Text Available In order to study the filter effect of the background winds on the propagation of gravity waves, a three-dimensional transfer function model is developed on the basis of the complex dispersion relation of internal gravity waves in a stratified dissipative atmosphere with background winds. Our model has successfully represented the main results of the ray tracing method, e.g. the trend of the gravity waves to travel in the anti-windward direction. Furthermore, some interesting characteristics are manifest as follows: (1 The method provides the distribution characteristic of whole wave fields which propagate in the way of the distorted concentric circles at the same altitude under the control of the winds. (2 Through analyzing the frequency and wave number response curve of the transfer function, we find that the gravity waves in a wave band of about 15–30 min periods and of about 200–400 km horizontal wave lengths are most likely to propagate to the 300-km ionospheric height. Furthermore, there is an obvious frequency deviation for gravity waves propagating with winds in the frequency domain. The maximum power of the transfer function with background winds is smaller than that without background winds. (3 The atmospheric winds may act as a directional filter that will permit gravity wave packets propagating against the winds to reach the ionospheric height with minimum energy loss.
The small K{sub {pi}} component in the K{sup *} wave functions
Energy Technology Data Exchange (ETDEWEB)
Xiao, C.W.; Aceti, F. [Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Centro Mixto Universidad de Valencia-CSIC, Valencia (Spain); Bayar, M. [Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Centro Mixto Universidad de Valencia-CSIC, Valencia (Spain); Kocaeli University, Department of Physics, Izmit (Turkey)
2013-02-15
We use a recently developed formalism which generalizes Weinberg's compositeness condition to partial waves higher than s -wave in order to determine the probability of having a K{sub {pi}} component in the K{sup *} wave function. A fit is made to the K{sub {pi}} phase shifts in p-wave, from where the coupling of K{sup *} to K{sub {pi}} and the K{sub {pi}} loop function are determined. These ingredients allow us to determine that the K{sup *} is a genuine state, different from a K{sub {pi}} component, in a proportion of about 80%. (orig.)
Li, Fubing; He, Qiong; Huang, Chengwu; Liu, Ke; Shao, Jinhua; Luo, Jianwen
2016-04-01
Pulse wave imaging (PWI) is an ultrasound-based method to visualize the propagation of pulse wave and to quantitatively estimate regional pulse wave velocity (PWV) of the arteries within the imaging field of view (FOV). To guarantee the reliability of PWV measurement, high frame rate imaging is required, which can be achieved by reducing the line density of ultrasound imaging or transmitting plane wave at the expense of spatial resolution and/or signal-to-noise ratio (SNR). In this study, a composite, full-view imaging method using motion matching was proposed with both high temporal and spatial resolution. Ultrasound radiofrequency (RF) data of 4 sub-sectors, each with 34 beams, including a common beam, were acquired successively to achieve a frame rate of ∼507 Hz at an imaging depth of 35 mm. The acceleration profiles of the vessel wall estimated from the common beam were used to reconstruct the full-view (38-mm width, 128-beam) image sequence. The feasibility of mapping local PWV variation along the artery using PWI technique was preliminarily validated on both homogeneous and inhomogeneous polyvinyl alcohol (PVA) cryogel vessel phantoms. Regional PWVs for the three homogeneous phantoms measured by the proposed method were in accordance with the sparse imaging method (38-mm width, 32-beam) and plane wave imaging method. Local PWV was estimated using the above-mentioned three methods on 3 inhomogeneous phantoms, and good agreement was obtained in both the softer (1.91±0.24 m/s, 1.97±0.27 m/s and 1.78±0.28 m/s) and the stiffer region (4.17±0.46 m/s, 3.99±0.53 m/s and 4.27±0.49 m/s) of the phantoms. In addition to the improved spatial resolution, higher precision of local PWV estimation in low SNR circumstances was also obtained by the proposed method as compared with the sparse imaging method. The proposed method might be helpful in disease detections through mapping the local PWV of the vascular wall. Copyright © 2016 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Franz Gross, Alfred Stadler
2010-09-01
We present the effective range expansions for the 1S0 and 3S1 scattering phase shifts, and the relativistic deuteron wave functions that accompany our recent high precision fits (with \\chi^2/N{data} \\simeq 1) to the 2007 world np data below 350 MeV. The wave functions are expanded in a series of analytical functions (with the correct asymptotic behavior at both large and small arguments) that can be Fourier-transformed from momentum to coordinate space and are convenient to use in any application. A fortran subroutine to compute these wave functions can be obtained from the authors.
Yan, Liwei; Yao, Zhi; Lin, Tao; Zhu, Qingtang; Qi, Jian; Gu, Liqiang; Fang, Jintao; Zhou, Xiang; Liu, Xiaolin
2017-10-18
Peripheral nerve injury therapy in the clinic remains less than satisfactory. The gold standard of treatment for long peripheral nerve defects is autologous nerve grafts; however, numerous clinical complications are associated with this treatment. As tissue engineering has developed, tissue-engineered nerve grafts (TENGs) have shown potential applications as alternatives to autologous nerve grafts. To verify the important role of the biomimetic pathway of fascicle design in TENGs, we designed an animal model to study the role of the precise matching of fascicles in the effectiveness of nerve function recovery. 24 Sprague-Dawley rats were divided randomly into three groups (eight/group) that corresponded to 100% fascicle matching (100%FM), 50%FM and 0%FM. We selected Sprague-Dawley rat long-gap (15 mm) sciatic nerve defects. In the 6 weeks after surgery, we found that the 100%FM group showed the most effective functional recovery among the three groups. The 100%FM group showed better functional recovery on the basis of the sciatic functional index than the 50%FM and 0%FM groups. According to histological evaluation, the 100%FM group showed more regenerating nerve fibres. Moreover, in terms of the prevention of muscle atrophy, the 100%FM group showed excellent physiological outcomes. The 100%FM as tissue-engineered scaffolds can enhance nerve regeneration and effective functional recovery after the repair of large nerve defects. The results of this study provide a theoretical basis for future TENG designs including biomimetic fascicle pathways for repairing long nerve defects.
Longitudinal wave function control in single quantum dots with an applied magnetic field
Cao, Shuo; Tang, Jing; Gao, Yunan; Sun, Yue; Qiu, Kangsheng; Zhao, Yanhui; He, Min; Shi, Jin-An; Gu, Lin; Williams, David A.; Sheng, Weidong; Jin, Kuijuan; Xu, Xiulai
2015-01-01
Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field. For a pure InAs quantum dot with a shape of pyramid or truncated pyramid, the hole wave function always occupies the base because of the less confinement at base, which induces a permanent dipole oriented from base to apex. With applying magnetic field along the base-apex direction, the hole wave function shrinks in the base plane. Because of the linear changing of the confinement for hole wave function from base to apex, the center of effective mass moves up during shrinking process. Due to the uniform confine potential for electrons, the center of effective mass of electrons does not move much, which results in a permanent dipole moment change and an inverted electron-hole alignment along the magnetic field direction. Manipulating the wave function longitudinally not only provides an alternative way to control the charge distribution with magnetic field but also a new method to tune electron-hole interaction in single quantum dots. PMID:25624018
Class of variational singlet wave functions for the Hubbard model away from half filling
Anderson, P. W.; Shastry, B. S.; Hristopulos, D.
1989-11-01
We present a class of variational wave functions for strong-coupling Heisenberg Hubbard models. These are written in the form of three factors-a pair of determinants and a Jastrow function-and are made out of orbitals, a la Hartree-Fock theory, which solve a fictitious one-body problem. The wave functions respect various constraints known from general principles and appear to be potentially useful in understanding the possible behavior of the models in quantitative terms.
Class of variational singlet wave functions for the Hubbard model away from half filling
Energy Technology Data Exchange (ETDEWEB)
Anderson, P.W. (Joseph Henry Laboratories of Physics, Princeton University, Princeton, New Jersey 08544 (USA)); Shastry, B.S. (AT T Bell Laboratories, 1D-234 Murray Hill, New Jersey 07974 (USA)); Hristopulos, D. (Joseph Henry Laboratories of Physics, Princeton University, Princeton, New Jersey 08544 (USA))
1989-11-01
We present a class of variational wave functions for strong-coupling Heisenberg Hubbard models. These are written in the form of three factors---a pair of determinants and a Jastrow function---and are made out of orbitals, {ital a} {ital la} Hartree-Fock theory, which solve a fictitious one-body problem. The wave functions respect various constraints known from general principles and appear to be potentially useful in understanding the possible behavior of the models in quantitative terms.
Iizuka, Masayuki; Reding, Mike
2005-05-01
To compare the morbidity, mortality, and functional recovery of patients who require percutaneous endoscopic gastrostomy (PEG) placement for the management of dysphagia after stroke. Retrospective case-matched controlled study. Acute stroke rehabilitation inpatient unit. Patients (N=193) who were admitted for stroke rehabilitation with a PEG tube in place from January 1, 1993, to December 31, 2002, were matched with 193 case controls without PEG. Patients and controls were within 90 days of stroke onset, and were matched for age, sex, type of stroke, FIM instrument score, duration from onset to stroke unit admission, and year of admission. Not applicable. Length of rehabilitation hospital stay, improvement in FIM scores, FIM efficiency score, need for transfer back to acute care hospital, diagnosis for which transfer was required, final discharge destination, and survival status. Significant differences were found between the 2 groups, PEG versus control, respectively, in the following variables: FIM efficiency (.42+/-.57 vs .56+/-.55, P =.016); need for transfer back to acute hospital (58/193 vs 23/193, P =.001); and survival status dead/alive (14/179 vs 3/190, P =.006). Nonsignificant differences were as follows: length of rehabilitation hospital stay (46.9+/-24.8d vs 43.3+/-19.7d, P =.11), improvement in total FIM score from admission to discharge (16.9+/-17.9 vs 21.0+/-15.5, P =.72), and final discharge destination home/institutional care (96/83 vs 101/89, P =.93). Pneumonia was the most frequent reason for transfer to acute care for patients with PEG. Patients who meet criteria for admission to a stroke rehabilitation unit and who have a PEG in place are at increased risk for medical complications and death. Those who survive, however, show similar functional recovery and rate of home discharge as case-matched controls.
Matrix-product-based projected wave functions ansatz for quantum many-body ground states
Chou, Chung-Pin; Pollmann, Frank; Lee, Ting-Kuo
2012-07-01
We introduce a projected wave function approach based on projection operators in the form of matrix-product operators (MPOs). Our approach allows us to variationally improve the short-range entanglement of a given trial wave function by optimizing the matrix elements of the MPOs while the long-range entanglement is contained in the initial guess of the wave function. The optimization is performed using standard variational Monte Carlo techniques. We demonstrate the efficiency of our approach by considering a one-dimensional model of interacting spinless fermions. In addition, we indicate how to generalize this approach to higher dimensions using projection operators which are based on tensor products.
Taylor, Peter R
2013-08-21
We propose the use of the singular value decomposition to decrease the storage required for wave function information. The specific case considered is determinantal full configuration interaction, but the same technique is readily applicable to truncated configuration interaction and coupled-cluster calculations of various types; as we discuss this is a reformulation of approximate methods that have been in use for some time, but our approach eliminates those approximations. Numerical examples support the contention that considerable compression of the wave function is possible without significant loss of accuracy: as expected a considerable amount of the information contained in the full CI wave function is redundant.
DEFF Research Database (Denmark)
Stroescu, Ionut Emanuel; Sørensen, Lasse; Frigaard, Peter Bak
2016-01-01
A non-linear stretching method was implemented for stream function theory to solve wave kinematics for physical conditions close to breaking waves in shallow waters, with wave heights limited by the water depth. The non-linear stretching method proves itself robust, efficient and fast, showing good...
Plummer, MD
1986-01-01
This study of matching theory deals with bipartite matching, network flows, and presents fundamental results for the non-bipartite case. It goes on to study elementary bipartite graphs and elementary graphs in general. Further discussed are 2-matchings, general matching problems as linear programs, the Edmonds Matching Algorithm (and other algorithmic approaches), f-factors and vertex packing.
When function mirrors structure: how slow waves are shaped by cortical layers
Directory of Open Access Journals (Sweden)
Cristiano Capone
2015-04-01
As the model predicted, we found that strips of early wave propagation reliably overlapped with the regions where maximum Up state duration and firing activity occurred, strengthening the duality between spontaneous activity and network structure. Finally, we matched the excitable strips with the slice cortical layers as identified by histology, finding a reliable overlap between such strips and L4 and L5 (see Figure 1E. Figure 1. A. Wavefronts for 2 modes of propagation. B. Average strips where wavefronts propagate earlier (black, and where Up states have maximum duration (green and magnitude (blue. C. Modulation of the connectivity parameter in the model. D. Nullclines under mean-field approximation varying levels of connectivity. and C are average firing rate and fatigue level, respectively. Circles, fixed points. Dark to light gray, different excitability levels as in C, respectively. E. Example match between strip of early wave propagation and slice’s layers.
Potential applications of low-energy shock waves in functional urology.
Wang, Hung-Jen; Cheng, Jai-Hong; Chuang, Yao-Chi
2017-08-01
A shock wave, which carries energy and can propagate through a medium, is a type of continuous transmitted sonic wave with a frequency of 16 Hz-20 MHz. It is accompanied by processes involving rapid energy transformations. The energy associated with shock waves has been harnessed and used for various applications in medical science. High-energy extracorporeal shock wave therapy is the most successful application of shock waves, and has been used to disintegrate urolithiasis for 30 years. At lower energy levels, however, shock waves have enhanced expression of vascular endothelial growth factor, endothelial nitric oxide synthase, proliferating cell nuclear antigen, chemoattractant factors and recruitment of progenitor cells; shock waves have also improved tissue regeneration. Low-energy shock wave therapy has been used clinically with musculoskeletal disorders, ischemic cardiovascular disorders and erectile dysfunction, through the mechanisms of neovascularization, anti-inflammation and tissue regeneration. Furthermore, low-energy shock waves have been proposed to temporarily increase tissue permeability and facilitate intravesical drug delivery. The present review article provides information on the basics of shock wave physics, mechanisms of action on the biological system and potential applications in functional urology. © 2017 The Japanese Urological Association.
Swift, Damon L.; Weltman, Judith Y.; Patrie, James T.; Barrett, Eugene J.; Gaesser, Glenn A.; Weltman, Arthur
2014-01-01
Objective We investigated endothelial function at rest and after a high-fat meal challenge in African American (AA) and Caucasian postmenopausal women matched for age, body mass index, percent fat and fitness level. Design Pilot study. Setting University of Virginia General Clinical Research Center. Participants: Eight AA and 8 Caucasian postmenopausal women. Intervention Participants underwent a VO2 peak treadmill protocol, percent fat assessment, and brachial artery flow-mediated dilation measurements (baseline and 4 hours following a high-fat meal). Main outcomes measures Baseline and postprandial flow mediated dilation (FMD) following a high-fat meal. Results FMD values were similar in AA (5.4%, 95% CI: 3.3, 7.4) and Caucasian women (4.0%, 95% CI: 2.0, 6.1). There was no significant change in FMD from baseline to four hours following the meal challenge within groups (AA: .9%, P=.397, Caucasian: 2.3%, P=.063) or between groups (P=.449), despite a significant increase in triglycerides (AA: 81.8 mg/dL, P<.001, Caucasian: 99.7 mg/dL, P=.004). Conclusions The present pilot study found that when postmenopausal AA and Caucasian women are matched for age, fitness and body composition, reported racial differences in resting endothelial function were not observed. Additionally, there were no racial differences in postprandial endothelial function or metabolism following a high-fat meal. PMID:23495621
The meaning of the wave function in search of the ontology of quantum mechanics
Gao, Shan
2017-01-01
At the heart of quantum mechanics lies the wave function, a powerful but mysterious mathematical object which has been a hot topic of debate from its earliest stages. Covering much of the recent debate and providing a comprehensive and critical review of competing approaches, this ambitious text provides new, decisive proof of the reality of the wave function. Aiming to make sense of the wave function in quantum mechanics and to find the ontological content of the theory, this book explores new ontological interpretations of the wave function in terms of random discontinuous motion of particles. Finally, the book investigates whether the suggested quantum ontology is complete in solving the measurement problem and if it should be revised in the relativistic domain. A timely addition to the literature on the foundations of quantum mechanics, this book is of value to students and researchers with an interest in the philosophy of physics. Presents a concise introduction to quantum mechanics, including the c...
Approximate analytical time-domain Green's functions for the Caputo fractional wave equation.
Kelly, James F; McGough, Robert J
2016-08-01
The Caputo fractional wave equation [Geophys. J. R. Astron. Soc. 13, 529-539 (1967)] models power-law attenuation and dispersion for both viscoelastic and ultrasound wave propagation. The Caputo model can be derived from an underlying fractional constitutive equation and is causal. In this study, an approximate analytical time-domain Green's function is derived for the Caputo equation in three dimensions (3D) for power law exponents greater than one. The Green's function consists of a shifted and scaled maximally skewed stable distribution multiplied by a spherical spreading factor 1/(4πR). The approximate one dimensional (1D) and two dimensional (2D) Green's functions are also computed in terms of stable distributions. Finally, this Green's function is decomposed into a loss component and a diffraction component, revealing that the Caputo wave equation may be approximated by a coupled lossless wave equation and a fractional diffusion equation.
National Research Council Canada - National Science Library
Banu Ünalmis Uzun
2017-01-01
We state the fractional Fourier transform and the continuous fractional wave packet transform as ways for analyzing persistent signals such as almost periodic functions and strong limit power signals...
Extracting the Green's function of attenuating heterogeneous acoustic media from uncorrelated waves.
Snieder, Roel
2007-05-01
The Green's function of acoustic or elastic wave propagation can, for loss-less media, be retrieved by correlating the wave field that is excited by random sources and is recorded at two locations. Here the generalization of this idea to attenuating acoustic waves in an inhomogeneous medium is addressed, and it is shown that the Green's function can be retrieved from waves that are excited throughout the volume by spatially uncorrelated injection sources with a power spectrum that is proportional to the local dissipation rate. For a finite volume, one needs both volume sources and sources at the bounding surface for the extraction of the Green's functions. For the special case of a homogeneous attenuating medium defined over a finite volume, the phase and geometrical spreading of the Green's function is correctly retrieved when the volume sources are ignored, but the attenuation is not.
Making a happy match between orbital-free density functional theory and information energy density
Alipour, Mojtaba
2015-08-01
In the field of computational chemistry within density functional theory (DFT), the orbital-free DFT (OF-DFT) can be considered as a promising approach for simulating large systems. In OF-DFT, only a single relation, the Euler equation, has to be solved independently from the number of electrons. In this work, the Euler equation of OF-DFT is rewritten through a new partition scheme for energy density functional. Next, based on information theory, we reformulate the resulting equation in terms of Onicescu information energy density. Plus, the new forms of Euler equation based on Shannon entropy and Fisher information are presented.
Structure of the channeling electrons wave functions under dynamical chaos conditions
Energy Technology Data Exchange (ETDEWEB)
Shul’ga, N.F. [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., Kharkov 61108 (Ukraine); V.N. Karazin National University, 4, Svodody Sq., Kharkov 61022 (Ukraine); Syshchenko, V.V., E-mail: syshch@yandex.ru [Belgorod National Research University, 85, Pobedy St., Belgorod 308015 (Russian Federation); Tarnovsky, A.I. [Belgorod National Research University, 85, Pobedy St., Belgorod 308015 (Russian Federation); Isupov, A.Yu. [Laboratory of High Energy Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow region (Russian Federation)
2016-03-01
The stationary wave functions of fast electrons axially channeling in the silicon crystal near [1 1 0] direction have been found numerically for integrable and non-integrable cases, for which the classical motion is regular and chaotic, respectively. The nodal structure of the wave functions in the quasi-classical region, where the energy levels density is high, is agreed with quantum chaos theory predictions.
Lee, Gibbeum; Cho, Yeunwoo
2018-01-01
A new semi-analytical approach is presented to solving the matrix eigenvalue problem or the integral equation in Karhunen-Loeve (K-L) representation of random data such as irregular ocean waves. Instead of direct numerical approach to this matrix eigenvalue problem, which may suffer from the computational inaccuracy for big data, a pair of integral and differential equations are considered, which are related to the so-called prolate spheroidal wave functions (PSWF). First, the PSWF is expressed as a summation of a small number of the analytical Legendre functions. After substituting them into the PSWF differential equation, a much smaller size matrix eigenvalue problem is obtained than the direct numerical K-L matrix eigenvalue problem. By solving this with a minimal numerical effort, the PSWF and the associated eigenvalue of the PSWF differential equation are obtained. Then, the eigenvalue of the PSWF integral equation is analytically expressed by the functional values of the PSWF and the eigenvalues obtained in the PSWF differential equation. Finally, the analytically expressed PSWFs and the eigenvalues in the PWSF integral equation are used to form the kernel matrix in the K-L integral equation for the representation of exemplary wave data such as ordinary irregular waves. It is found that, with the same accuracy, the required memory size of the present method is smaller than that of the direct numerical K-L representation and the computation time of the present method is shorter than that of the semi-analytical method based on the sinusoidal functions.
Modeling the Pulse Signal by Wave-Shape Function and Analyzing by Synchrosqueezing Transform.
Directory of Open Access Journals (Sweden)
Hau-Tieng Wu
Full Text Available We apply the recently developed adaptive non-harmonic model based on the wave-shape function, as well as the time-frequency analysis tool called synchrosqueezing transform (SST to model and analyze oscillatory physiological signals. To demonstrate how the model and algorithm work, we apply them to study the pulse wave signal. By extracting features called the spectral pulse signature, and based on functional regression, we characterize the hemodynamics from the radial pulse wave signals recorded by the sphygmomanometer. Analysis results suggest the potential of the proposed signal processing approach to extract health-related hemodynamics features.
Anderson, Barrett G; Potretzke, Aaron M; Du, Kefu; Vetter, Joel; Figenshau, R Sherburne
2017-08-31
In the interest of renal functional preservation, partial nephrectomy has supplanted radical nephrectomy as the preferred treatment for T1 renal masses. This procedure usually involves the induction of renal warm ischemia by clamping the hilar vessels prior to tumor excision. Performing robot-assisted partial nephrectomy (RAPN) "off-clamp" can theoretically prevent renal functional loss associated with warm ischemia. We describe our institutional experience and compare perioperative and renal functional outcomes using a propensity score matched cohort. We conducted a retrospective comparison from a prospectively maintained database of all patients who underwent RAPN from 2009 to 2015. Of those patients, 143 underwent off-clamp RAPN. Fifty off-clamp RAPN patients were propensity score matched with fifty clamped RAPN patients based on renal function, tumor size, and R.E.N.A.L. nephrometry score. The cohorts were compared across demographics, operative information, perioperative outcomes, and renal functional outcomes. For all off-clamp RAPN patients, mean nephrometry score was 7.1, mean estimated blood loss (EBL) was 236.9 mL, perioperative complication rate was 7.7%, and mean decrease in estimated glomerular filtration rate (eGFR) was 7.1% at a median follow-up of 9.2 months. In the propensity score matched cohorts, off-clamp RAPN resulted in a shorter mean operative time (172.0 versus 196.0 min, p = 0.025) and a lower mean EBL (179.7 versus 283.2 mL, p = 0.046). A lower complication rate of 6.0% in the off-clamp group compared with 20.0% in the clamped group approached significance (p = 0.071). Mean preoperative eGFR was similar in both cohorts. Importantly, there was no significant difference in decrease in eGFR between the clamped cohort (9.8%) and off-clamp cohort (11.9%) at a median follow-up of 9.0 months (p = 0.620). Off-clamp RAPN did not result in improved renal functional preservation in our experience. Surprisingly, the off-clamp cohort
Energy Technology Data Exchange (ETDEWEB)
McKechnie, Scott [Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Booth, George H. [Theory and Simulation of Condensed Matter, King’s College London, The Strand, London WC2R 2LS (United Kingdom); Cohen, Aron J. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom); Cole, Jacqueline M., E-mail: jmc61@cam.ac.uk [Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Argonne National Laboratory, 9700 S Cass Avenue, Argonne, Illinois 60439 (United States)
2015-05-21
The best practice in computational methods for determining vertical ionization energies (VIEs) is assessed, via reference to experimentally determined VIEs that are corroborated by highly accurate coupled-cluster calculations. These reference values are used to benchmark the performance of density functional theory (DFT) and wave function methods: Hartree-Fock theory, second-order Møller-Plesset perturbation theory, and Electron Propagator Theory (EPT). The core test set consists of 147 small molecules. An extended set of six larger molecules, from benzene to hexacene, is also considered to investigate the dependence of the results on molecule size. The closest agreement with experiment is found for ionization energies obtained from total energy difference calculations. In particular, DFT calculations using exchange-correlation functionals with either a large amount of exact exchange or long-range correction perform best. The results from these functionals are also the least sensitive to an increase in molecule size. In general, ionization energies calculated directly from the orbital energies of the neutral species are less accurate and more sensitive to an increase in molecule size. For the single-calculation approach, the EPT calculations are in closest agreement for both sets of molecules. For the orbital energies from DFT functionals, only those with long-range correction give quantitative agreement with dramatic failing for all other functionals considered. The results offer a practical hierarchy of approximations for the calculation of vertical ionization energies. In addition, the experimental and computational reference values can be used as a standardized set of benchmarks, against which other approximate methods can be compared.
Bruni, S.; Llombart, N.; Neto, A.; Gerini, G.; Maci, S.
2004-01-01
A method is proposed for the analysis of arrays of linear printed antennas. After the formulation of pertinent set of integral equations, the appropriate equivalent currents of the Method of Moments are represented in terms of two sets of entire domain basis functions. These functions synthesize on
Gluon fragmentation into a vector charmonium J/psi considering the effect of meson wave function
Directory of Open Access Journals (Sweden)
Seyed Mohammad Moosavi nejad
2017-05-01
Full Text Available Studying the production or decay processes of heavy quarkonia (the bound state of heavy quark-antiquark is a powerful tool to test our understanding of strong interaction dynamics and QCD theory. Fragmentation is the dominant production mechanism for heavy quarkonia with large transverse momentum. The fragmentation refers to the production process of a parton with high transverse momentum which subsequently decays into a heavy quarkonia. In all previous manuscript where the fragmentation functions of heavy mesons or baryons are calculated, authors have used the approximation of a Dirac delta function for the meson wave function. In the present paper by working in a perturbative QCD framework and by considering the effect of meson wave functions we calculate the fragmentation function of a gluon into a spin-triplet S-wave charmonium J/psi. To consider the real aspect of meson bound state we apply a mesonic wave function which is different of Dirac delta function and is a nonrelativistic limit of the Bethe-Salpeter equation. Finally, we present our numerical results and show that how the proposed wave function improves the previous results.
Pratt, M. J.; Aleqabi, G. I.; Wysession, M. E.; Wiens, D. A.; Nyblade, A.; Shore, P.; Rambolamanana, G.; Tsiriandrimanana, R.; Andriampenomanana Ny Ony, F. S. T.
2014-12-01
The continental crust and upper mantle velocity structure beneath Madagascar remained poorly constrained until recent deployments of broadband seismic instrumentation across the island. The MACOMO (MAdagascar, COmoros and MOzambique), RHUM-RUM (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel) and the Madagascar Seismic Profile experiments have opened up this region to be studied in detail for the first time. The island is an amalgamation of an Archean craton, associated with the Western Dhawar craton of southern India, and a series of Proterozoic terranes that comprise the backbone of the island (Tucker et al., 2010). A receiver-function analysis has provided both the first Moho depth measurements and spatially discrete 1-D shear velocity results that matched well with known tectonic regions. To provide a more continuous 2-D and 3-D velocity structure map, teleseismic surface wave analysis is employed. Using Helmholtz tomography as implemented by the ASWMS package (Ge, Gaherty and Hutko; 2014), we are able to map phase velocities from the cross-correlation of station pairs at periods 20-100 s. At periods 20-40 s our results compare well with ambient noise analysis results (see poster by Wysession et al. (this meeting)). The prominent features of these results are a distinct low phase-velocity sector beneath the central Itasy region, with a secondary low phase-velocity region to the north of the island. Both the central part of the island and the northern region have experienced geothermal activity in recent times as well as volcanic activity within the last 10,000 years. This may suggest that the crust and underlying mantle in these regions remains at relatively higher temperatures than the surrounding rock. Combining this information with receiver-function analysis, we jointly invert our data for the shear velocity structure. These analyses will constrain the upper mantle seismic velocities in the region, allowing further analysis from body waves to
DEFF Research Database (Denmark)
Ibsen, Lars Bo
2008-01-01
Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many...... times smaller it remains very high. For example, whilst there is enough potential wave power off the UK to supply the electricity demands several times over, the economically recoverable resource for the UK is estimated at 25% of current demand; a lot less, but a very substantial amount nonetheless....
Evans, M D R; Kelley, Paul; Kelley, Jonathan
2017-01-01
University days generally start at fixed times in the morning, often early morning, without regard to optimal functioning times for students with different chronotypes. Research has shown that later starting times are crucial to high school students' sleep, health, and performance. Shifting the focus to university, this study used two new approaches to determine ranges of start times that optimize cognitive functioning for undergraduates. The first is a survey-based, empirical model (SM), and the second a neuroscience-based, theoretical model (NM). The SM focused on students' self-reported chronotype and times they feel at their best. Using this approach, data from 190 mostly first and second year university students were collected and analyzed to determine optimal times when cognitive performance can be expected to be at its peak. The NM synthesized research in sleep, circadian neuroscience, sleep deprivation's impact on cognition, and practical considerations to create a generalized solution to determine the best learning hours. Strikingly the SM and NM results align with each other and confirm other recent research in indicating later start times. They add several important points: (1) They extend our understanding by showing that much later starting times (after 11 a.m. or 12 noon) are optimal; (2) Every single start time disadvantages one or more chronotypes; and (3) The best practical model may involve three alternative starting times with one afternoon shared session. The implications are briefly considered.
Bayesian extraction of the parton distribution amplitude from the Bethe-Salpeter wave function
Gao, Fei; Chang, Lei; Liu, Yu-xin
2017-07-01
We propose a new numerical method to compute the parton distribution amplitude (PDA) from the Euclidean Bethe-Salpeter wave function. The essential step is to extract the weight function in the Nakanishi representation of the Bethe-Salpeter wave function in Euclidean space, which is an ill-posed inversion problem, via the maximum entropy method (MEM). The Nakanishi weight function as well as the corresponding light-front parton distribution amplitude (PDA) can be well determined. We confirm prior work on PDA computations, which was based on different methods.
Bayesian extraction of the parton distribution amplitude from the Bethe–Salpeter wave function
Directory of Open Access Journals (Sweden)
Fei Gao
2017-07-01
Full Text Available We propose a new numerical method to compute the parton distribution amplitude (PDA from the Euclidean Bethe–Salpeter wave function. The essential step is to extract the weight function in the Nakanishi representation of the Bethe–Salpeter wave function in Euclidean space, which is an ill-posed inversion problem, via the maximum entropy method (MEM. The Nakanishi weight function as well as the corresponding light-front parton distribution amplitude (PDA can be well determined. We confirm prior work on PDA computations, which was based on different methods.
Matching Supernovae to Galaxies
Kohler, Susanna
2016-12-01
developed a new automated algorithm for matching supernovae to their host galaxies. Their work builds on currently existing algorithms and makes use of information about the nearby galaxies, accounts for the uncertainty of the match, and even includes a machine learning component to improve the matching accuracy.Gupta and collaborators test their matching algorithm on catalogs of galaxies and simulated supernova events to quantify how well the algorithm is able to accurately recover the true hosts.Successful MatchingThe matching algorithms accuracy (purity) as a function of the true supernova-host separation, the supernova redshift, the true hosts brightness, and the true hosts size. [Gupta et al. 2016]The authors find that when the basic algorithm is run on catalog data, it matches supernovae to their hosts with 91% accuracy. Including the machine learning component, which is run after the initial matching algorithm, improves the accuracy of the matching to 97%.The encouraging results of this work which was intended as a proof of concept suggest that methods similar to this could prove very practical for tackling future survey data. And the method explored here has use beyond matching just supernovae to their host galaxies: it could also be applied to other extragalactic transients, such as gamma-ray bursts, tidal disruption events, or electromagnetic counterparts to gravitational-wave detections.CitationRavi R. Gupta et al 2016 AJ 152 154. doi:10.3847/0004-6256/152/6/154
Correlated Monte Carlo wave functions for the atoms He through Ne
Schmidt, K. E.; Moskowitz, J. W.
1990-09-01
We apply the variational Monte Carlo method to the atoms He through Ne. Our trial wave function is of the form introduced by Boys and Handy. We use the Monte Carlo method to calculate the first and second derivatives of an unreweighted variance and apply Newton's method to minimize this variance. We motivate the form of the correlation function using the local current conservation arguments of Feynman and Cohen. Using a self-consistent field wave function multiplied by a Boys and Handy correlation function, we recover a large fraction of the correlation energy of these atoms. We give the value of all variational parameters necessary to reproduce our wave functions. The method can be extended easily to other atoms and to molecules.
Cheng, Jin; Yu, Kuang; Libisch, Florian; Dieterich, Johannes M; Carter, Emily A
2017-03-14
Quantum mechanical embedding theories partition a complex system into multiple spatial regions that can use different electronic structure methods within each, to optimize trade-offs between accuracy and cost. The present work incorporates accurate but expensive correlated wave function (CW) methods for a subsystem containing the phenomenon or feature of greatest interest, while self-consistently capturing quantum effects of the surroundings using fast but less accurate density functional theory (DFT) approximations. We recently proposed two embedding methods [for a review, see: Acc. Chem. Res. 2014 , 47 , 2768 ]: density functional embedding theory (DFET) and potential functional embedding theory (PFET). DFET provides a fast but non-self-consistent density-based embedding scheme, whereas PFET offers a more rigorous theoretical framework to perform fully self-consistent, variational CW/DFT calculations [as defined in part 1, CW/DFT means subsystem 1(2) is treated with CW(DFT) methods]. When originally presented, PFET was only tested at the DFT/DFT level of theory as a proof of principle within a planewave (PW) basis. Part 1 of this two-part series demonstrated that PFET can be made to work well with mixed Gaussian type orbital (GTO)/PW bases, as long as optimized GTO bases and consistent electron-ion potentials are employed throughout. Here in part 2 we conduct the first PFET calculations at the CW/DFT level and compare them to DFET and full CW benchmarks. We test the performance of PFET at the CW/DFT level for a variety of types of interactions (hydrogen bonding, metallic, and ionic). By introducing an intermediate CW/DFT embedding scheme denoted DFET/PFET, we show how PFET remedies different types of errors in DFET, serving as a more robust type of embedding theory.
Yao, Yudong; Shao, Charles; Jothianandan, Desingarao; Tcherepanov, Andrew; Shouval, Harel; Sacktor, Todd Charlton
2013-01-01
PKMζ is an autonomously active, atypical protein kinase C (aPKC) isoform that is both necessary and sufficient for maintaining long-term potentiation (LTP) and long-term memory. The myristoylated ζ-pseudosubstrate peptide, ZIP, potently inhibits PKMζ biochemically in vitro, within cultured cells, and within neurons in hippocampal slices, and reverses LTP maintenance and erases long-term memory storage. A recent study (Wu-Zhang et al., 2012), however, suggested ZIP was not effective on a PKMζ fusion protein overexpressed in cultured cells. Chelerythrine, a redox-sensitive PKC inhibitor that inhibits PKMζ and disrupts LTP maintenance and memory storage, was also reported by Wu-Zhang et al. (2012) not to inhibit the expressed PKMζ fusion protein. However, the efficacy of inhibitors on endogenous enzymes in cells may not be adequately assessed in expression systems in which levels of expression of exogenous enzymes greatly exceed those of endogenous enzymes. Thus, we show, biochemically, that when PKMζ reaches a level beyond that necessary for substrate phosphorylation such that much of the enzyme is excess or 'spare' kinase, ZIP and chelerythrine do not effectively block substrate phosphorylation. We also show that the cellular overexpression techniques used by Wu-Zhang et al. (2012) increase kinase levels ~30-40 fold above normal levels in transfected cells. Using a mathematical model we show that at such level of overexpression, standard concentrations of inhibitor should have no noticeable effect. Furthermore, we demonstrate the standard concentrations of ZIP, but not scrambled ZIP, inhibit the ability of PKMζ to potentiate AMPAR responses at postsynaptic sites, the physiological function of the kinase. Wu-Zhang et al. (2012) had also claimed that staurosporine, a general kinase inhibitor that does not effectively inhibit PKMζ biochemically in vitro, nonetheless indirectly blocked the PKMζ fusion protein overexpressed in cultured cells by inhibiting
Tkacz, Joseph P.; Tomporowski, Phillip D.; Bustamante, Eduardo E.
2015-01-01
Purpose This study tested whether participation in organized physical activity (active vs. inactive) or weight status (normal weight vs. overweight or obese) independently relate to hildren’s cognition, using a matched-pairs design. Design and Methods Normal weight, active children (8–11 yrs, 5th–75th percentile BMI) were recruited from extracurricular physical activity programs while normal weight inactive (5th–75th percentile BMI) and overweight inactive children (BMI ≥85th percentile) were recruited from local Augusta, Georgia area schools. Measures included the Cognitive Assessment System, anthropometrics, and parent- and self-report of physical activity. Paired t-tests compared cognition scores between matched groups of normal weight active vs. normal weight inactive (N=24 pairs), normal weight inactive vs. overweight inactive (N=21 pairs), and normal weight active vs. overweight inactive children (N=16 pairs). Children in each comparison were matched for race, gender, age, and socioeconomic status. Results Normal weight active children had higher Planning (M±SD=109±11 vs. 100±11, p=.011) and Attention scores (108±11 vs. 100±11, p=013) than overweight inactive children. Normal weight inactive children had higher Attention scores than overweight inactive children (105±13 vs. 93±12, p=008). When compared to normal weight inactive children, normal weight active children had higher Planning (113±10 vs. 102±13, p=008) and marginally higher Attention scores (111±11 vs. 104±12, p=06). Conclusion Findings suggest independent associations of children’s weight status with selective attention, and physical activity with higher-order processes of executive function. PMID:26252198
Function of a fly motion-sensitive neuron matches eye movements during free flight.
Directory of Open Access Journals (Sweden)
Roland Kern
2005-06-01
Full Text Available Sensing is often implicitly assumed to be the passive acquisition of information. However, part of the sensory information is generated actively when animals move. For instance, humans shift their gaze actively in a sequence of saccades towards interesting locations in a scene. Likewise, many insects shift their gaze by saccadic turns of body and head, keeping their gaze fixed between saccades. Here we employ a novel panoramic virtual reality stimulator and show that motion computation in a blowfly visual interneuron is tuned to make efficient use of the characteristic dynamics of retinal image flow. The neuron is able to extract information about the spatial layout of the environment by utilizing intervals of stable vision resulting from the saccadic viewing strategy. The extraction is possible because the retinal image flow evoked by translation, containing information about object distances, is confined to low frequencies. This flow component can be derived from the total optic flow between saccades because the residual intersaccadic head rotations are small and encoded at higher frequencies. Information about the spatial layout of the environment can thus be extracted by the neuron in a computationally parsimonious way. These results on neuronal function based on naturalistic, behaviourally generated optic flow are in stark contrast to conclusions based on conventional visual stimuli that the neuron primarily represents a detector for yaw rotations of the animal.
A functional renormalization method for wave propagation in random media
Lamagna, Federico; Calzetta, Esteban
2017-08-01
We develop the exact renormalization group approach as a way to evaluate the effective speed of the propagation of a scalar wave in a medium with random inhomogeneities. We use the Martin-Siggia-Rose formalism to translate the problem into a non equilibrium field theory one, and then consider a sequence of models with a progressively lower infrared cutoff; in the limit where the cutoff is removed we recover the problem of interest. As a test of the formalism, we compute the effective dielectric constant of an homogeneous medium interspersed with randomly located, interpenetrating bubbles. A simple approximation to the renormalization group equations turns out to be equivalent to a self-consistent two-loops evaluation of the effective dielectric constant.
Propagation of ultrasonic Love waves in nonhomogeneous elastic functionally graded materials.
Kiełczyński, P; Szalewski, M; Balcerzak, A; Wieja, K
2016-02-01
This paper presents a theoretical study of the propagation behavior of ultrasonic Love waves in nonhomogeneous functionally graded elastic materials, which is a vital problem in the mechanics of solids. The elastic properties (shear modulus) of a semi-infinite elastic half-space vary monotonically with the depth (distance from the surface of the material). The Direct Sturm-Liouville Problem that describes the propagation of Love waves in nonhomogeneous elastic functionally graded materials is formulated and solved by using two methods: i.e., (1) Finite Difference Method, and (2) Haskell-Thompson Transfer Matrix Method. The dispersion curves of phase and group velocity of surface Love waves in inhomogeneous elastic graded materials are evaluated. The integral formula for the group velocity of Love waves in nonhomogeneous elastic graded materials has been established. The effect of elastic non-homogeneities on the dispersion curves of Love waves is discussed. Two Love wave waveguide structures are analyzed: (1) a nonhomogeneous elastic surface layer deposited on a homogeneous elastic substrate, and (2) a semi-infinite nonhomogeneous elastic half-space. Obtained in this work, the phase and group velocity dispersion curves of Love waves propagating in the considered nonhomogeneous elastic waveguides have not previously been reported in the scientific literature. The results of this paper may give a deeper insight into the nature of Love waves propagation in elastic nonhomogeneous functionally graded materials, and can provide theoretical guidance for the design and optimization of Love wave based devices. Copyright © 2015 Elsevier B.V. All rights reserved.
Lovász, László
2009-01-01
This book surveys matching theory, with an emphasis on connections with other areas of mathematics and on the role matching theory has played, and continues to play, in the development of some of these areas. Besides basic results on the existence of matchings and on the matching structure of graphs, the impact of matching theory is discussed by providing crucial special cases and nontrivial examples on matroid theory, algorithms, and polyhedral combinatorics. The new Appendix outlines how the theory and applications of matching theory have continued to develop since the book was first publish
Kinetic theory for distribution functions of wave-particle interactions in plasmas.
Kominis, Y; Ram, A K; Hizanidis, K
2010-06-11
The evolution of a charged particle distribution function under the influence of coherent electromagnetic waves in a plasma is determined from kinetic theory. For coherent waves, the dynamical phase space of particles is an inhomogeneous mix of chaotic and regular orbits. The persistence of long time correlations between the particle motion and the phase of the waves invalidates any simplifying Markovian or statistical assumptions--the basis for usual quasilinear theories. The generalized formalism in this Letter leads to a hierarchy of evolution equations for the reduced distribution function. The evolution operators, in contrast to the quasilinear theories, are time dependent and nonsingular and include the rich phase space dynamics of particles interacting with coherent waves.
Basis of symmetric polynomials for many-boson light-front wave functions.
Chabysheva, Sophia S; Hiller, John R
2014-12-01
We provide an algorithm for the construction of orthonormal multivariate polynomials that are symmetric with respect to the interchange of any two coordinates on the unit hypercube and are constrained to the hyperplane where the sum of the coordinates is one. These polynomials form a basis for the expansion of bosonic light-front momentum-space wave functions, as functions of longitudinal momentum, where momentum conservation guarantees that the fractions are on the interval [0,1] and sum to one. This generalizes earlier work on three-boson wave functions to wave functions for arbitrarily many identical bosons. A simple application in two-dimensional ϕ(4) theory illustrates the use of these polynomials.
Baumeiste, K. J.
1983-01-01
A time-dependent finite difference formulation to the inhomogeneous wave equation is derived for plane wave propagation with harmonic noise sources. The difference equation and boundary conditions are developed along with the techniques to simulate the Dirac delta function associated with a concentrated noise source. Example calculations are presented for the Green's function and distributed noise sources. For the example considered, the desired Fourier transformed acoustic pressures are determined from the transient pressures by use of a ramping function and an integration technique, both of which eliminates the nonharmonic pressure associated with the initial transient.
Baumeister, K. J.
1983-01-01
A time-dependent finite difference formulation to the inhomogeneous wave equation is derived for plane wave propagation with harmonic noise sources. The difference equation and boundary conditions are developed along with the techniques to simulate the Dirac delta function associated with a concentrated noise source. Example calculations are presented for the Green's function and distributed noise sources. For the example considered, the desired Fourier transformed acoustic pressures are determined from the transient pressures by use of a ramping function and an integration technique, both of which eliminates the nonharmonic pressure associated with the initial transient.
EFFICIENT COMPUTATION OF PROLATE SPHEROIDAL WAVE FUNCTIONS IN RADIO ASTRONOMICAL SOURCE MODELING
Noorishad, Parisa; Yatawatta, Sarod
2011-01-01
The application of orthonormal basis functions such as Prolate Spheroidal Wave Functions (PSWF) for accurate source modeling in radio astronomy has been comprehensively studied. They are of great importance for high fidelity, high dynamic range imaging with new radio telescopes as well as
Directory of Open Access Journals (Sweden)
Elan D. Louis
2015-05-01
Full Text Available Background: An understanding of the functional aspects of gait and balance has wide ramifications. Individuals with balance disorders often restrict physical activity, travel, and social commitments to avoid falling, and loss of balance confidence, itself, is a source of disability. We studied the functional aspects of gait in patients with essential tremor (ET, placing their findings within the context of two other neurological disorders (Parkinson’s disease [PD] and dystonia and comparing them with age‐matched controls. Methods: We administered the six‐item Activities of Balance Confidence (ABC‐6 Scale and collected data on number of falls and near‐falls, and use of walking aids in 422 participants (126 ET, 77 PD, 46 dystonia, 173 controls. Results: Balance confidence was lowest in PD, intermediate in ET, and relatively preserved in dystonia compared with controls. This ordering reoccurred for each of the six ABC‐6 items. The number of near‐falls and falls followed a similar ordering. Use of canes, walkers, and wheelchairs was elevated in ET and even greater in PD. Several measures of balance confidence (ABC‐6 items 1, 4, 5, and 6 were lower in torticollis cases than in those with blepharospasm, although the two groups did not differ with respect to falls or use of walking aids. Discussion: Lower balance confidence, increased falls, and greater need for walking aids are variably features of a range of movement disorder patients compared to age‐matched controls. While most marked among PD patients, these issues affected ET patients as well and, to a small degree, some patients with dystonia.
Prolate Spheroidal Wave Functions, Quadrature, Interpolation, And Asymptotic Formulae
Xiao, H
2001-01-01
Whenever physical signals are measured or generated, the results tend to be band-limited (i.e. to have compactly supported Fourier transforms). Indeed, measurements of electromagnetic and acoustic data are band-limited due to the oscillatory character of the processes that have generated the quantities being measured. When the signals being measured come from heat propagation or diffusion processes, they are (practically speaking) band-limited, since the underlying physical processes operate as low- pass filters. The importance of band-limited functions has been recognized for hundreds of years; classical Fourier analysis can be viewed as an apparatus for dealing with such functions. When band-limited functions are defined on the whole line (or on the circle), classical tools are very satisfactory. However, in many cases, we are confronted with band- limited functions defined on intervals (or, more generally, on compact regions in R n). In this environment, standard tools based on polynomials are often effe...
Linear density response function in the projector augmented wave method
DEFF Research Database (Denmark)
Yan, Jun; Mortensen, Jens Jørgen; Jacobsen, Karsten Wedel
2011-01-01
functions of Si, C, SiC, AlP, and GaAs compare well with previous calculations. While optical properties of semiconductors, in particular excitonic effects, are generally not well described by ALDA, we obtain excellent agreement with experiments for the surface loss function of graphene and the Mg(0001......) surface with plasmon energies deviating by less than 0.2 eV. Finally, the method is applied to study the influence of substrates on the plasmon excitations in graphene....
Riemann zeta function from wave-packet dynamics
DEFF Research Database (Denmark)
Mack, R.; Dahl, Jens Peder; Moya-Cessa, H.
2010-01-01
We show that the time evolution of a thermal phase state of an anharmonic oscillator with logarithmic energy spectrum is intimately connected to the generalized Riemann zeta function zeta(s, a). Indeed, the autocorrelation function at a time t is determined by zeta (sigma + i tau, a), where sigma...... is governed by the temperature of the thermal phase state and tau is proportional to t. We use the JWKB method to solve the inverse spectral problem for a general logarithmic energy spectrum; that is, we determine a family of potentials giving rise to such a spectrum. For large distances, all potentials...
Symmetric multivariate polynomials as a basis for three-boson light-front wave functions.
Chabysheva, Sophia S; Elliott, Blair; Hiller, John R
2013-12-01
We develop a polynomial basis to be used in numerical calculations of light-front Fock-space wave functions. Such wave functions typically depend on longitudinal momentum fractions that sum to unity. For three particles, this constraint limits the two remaining independent momentum fractions to a triangle, for which the three momentum fractions act as barycentric coordinates. For three identical bosons, the wave function must be symmetric with respect to all three momentum fractions. Therefore, as a basis, we construct polynomials in two variables on a triangle that are symmetric with respect to the interchange of any two barycentric coordinates. We find that, through the fifth order, the polynomial is unique at each order, and, in general, these polynomials can be constructed from products of powers of the second- and third-order polynomials. The use of such a basis is illustrated in a calculation of a light-front wave function in two-dimensional ϕ(4) theory; the polynomial basis performs much better than the plane-wave basis used in discrete light-cone quantization.
Off-Shell Photon Longitudinal Light-Cone Wave Function at Leading Twist
Zhu, Kai; Liu, Jueping; Yu, Ran
The leading twist longitudinal virtual photon light-cone wave function, ϕγ‖(u, P2), is calculated within the framework of the low-energy effective theory arising from the instanton model of QCD vacuum. Corresponding to the non-perturbative effects at low-energy scale, a suitable regularization scale T is fixed by analysing the differential behavior of the photon wave function on the internal transverse momentum cut-off in the light-cone frame. The coupling constant, Fγ(P2), of the quark-antiquark vector current to the virtual photon state is also obtained by imposing the normalization condition. The feature of the obtained photon wave function has been discussed at the end as well as the coupling constant.
Trial wave functions for a composite Fermi liquid on a torus
Fremling, M.; Moran, N.; Slingerland, J. K.; Simon, S. H.
2018-01-01
We study the two-dimensional electron gas in a magnetic field at filling fraction ν =1/2 . At this filling the system is in a gapless state which can be interpreted as a Fermi liquid of composite fermions. We construct trial wave functions for the system on a torus, based on this idea, and numerically compare these to exact wave functions for small systems found by exact diagonalization. We find that the trial wave functions give an excellent description of the ground state of the system, as well as its charged excitations, in all momentum sectors. We analyze the dispersion of the composite fermions and the Berry phase associated with dragging a single fermion around the Fermi surface and comment on the implications of our results for the current debate on whether composite fermions are Dirac fermions.
Casanova, David; Krylov, Anna I.
2016-01-01
A new method for quantifying the contributions of local excitation, charge resonance, and multiexciton configurations in correlated wave functions of multichromophoric systems is presented. The approach relies on fragment-localized orbitals and employs spin correlators. Its utility is illustrated by calculations on model clusters of hydrogen, ethylene, and tetracene molecules using adiabatic restricted-active-space configuration interaction wave functions. In addition to the wave function analysis, this approach provides a basis for a simple state-specific energy correction accounting for insufficient description of electron correlation. The decomposition scheme also allows one to compute energies of the diabatic states of the local excitonic, charge-resonance, and multi-excitonic character. The new method provides insight into electronic structure of multichromophoric systems and delivers valuable reference data for validating excitonic models.
Yum, H N; Jang, Y J; Liu, X; Shahriar, M S
2012-08-13
In a white light cavity (WLC), the group velocity is superluminal over a finite bandwidth. For a WLC-based data buffering system we recently proposed, it is important to visualize the behavior of pulses inside such a cavity. The conventional plane wave transfer functions, valid only over space that is translationally invariant, cannot be used for the space inside WLC or any cavity, which is translationally variant. Here, we develop the plane wave spatio temporal transfer function (PWSTTF) method to solve this problem, and produce visual representations of a Gaussian input pulse incident on a WLC, for all times and positions.
Hartle-Hawking wave function and large-scale power suppression of CMB
Yeom, Dong-han
2018-01-01
In this presentation, we first describe the Hartle-Hawking wave function in the Euclidean path integral approach. After we introduce perturbations to the background instanton solution, following the formalism developed by Halliwell-Hawking and Laflamme, one can obtain the scale-invariant power spectrum for small-scales. We further emphasize that the Hartle-Hawking wave function can explain the large-scale power suppression by choosing suitable potential parameters, where this will be a possible window to confirm or falsify models of quantum cosmology. Finally, we further comment on possible future applications, e.g., Euclidean wormholes, which can result in distinct signatures to the power spectrum.
Relativistic treatment of pion wave functions in the annihilation p¯ p→ π- π+
El-Bennich, B.; Kloet, W. M.
2004-09-01
Quark model intrinsic wave functions of highly energetic pions in the reaction p¯ p→ π- π+ are subjected to a relativistic treatment. The annihilation is described in a constituent quark model with A2 and R2 flavor-flux topology, and the annihilated quark-antiquark pairs are in 3P0 and 3S1 states. We study the effects of pure Lorentz transformations on the antiquark and quark spatial wave functions and their respective spinors in the pion. The modified quark geometry of the pion has considerable impact on the angular dependence of the annihilation mechanisms.
Transfer function and near-field detection of evanescent waves
DEFF Research Database (Denmark)
Radko, Ylia P.; Bozhevolnyi, Sergey I.; Gregersen, Niels
2006-01-01
for the transfer function, which is derived by introducing an effective pointof (dipolelike) detection inside the probe tip. It is found to be possible to fit reasonably well both the experimental and the simulation data for evanescent field components, implying that the developed approximation of the near-field...... of collection and illumination modes. Making use of a collection near-field microscope with a similar fiber tip illuminated by an evanescent field, we measure the collected power as a function of the field spatial frequency in different polarization configurations. Considering a two-dimensional probe...... configuration, numerical simulations of detection efficiency based on the eigenmode expansion technique are carried out for different tip apex angles. The detection roll-off for high spatial frequencies observed in the experiment and obtained during the simulations is fitted using a simple expression...
Interacting relativistic quantum dynamics for multi-time wave functions
Directory of Open Access Journals (Sweden)
Lienert Matthias
2016-01-01
Full Text Available In this paper, we report on recent progress about a rigorous and manifestly covariant interacting model for two Dirac particles in 1+1 dimensions [9, 10]. It is formulated using the multi-time formalism of Dirac, Tomonaga and Schwinger. The mechanism of interaction is a relativistic generalization of contact interactions, and it is achieved going beyond the usual functional-analytic Hamiltonian method.
Wave function properties of a single and a system of magnetic flux tube(s) oscillations
Esmaeili, Shahriar; Nasiri, Mojtaba; Dadashi, Neda; Safari, Hossein
2016-10-01
In this study, the properties of wave functions of the MHD oscillations for a single and a system of straight flux tubes are investigated. Magnetic flux tubes with a straight magnetic field and longitudinal density stratification were considered in zero-β approximation. A single three-dimensional wave equation (eigenvalue problem) is solved for longitudinal component of the perturbed magnetic field using the finite element method. Wave functions (eigenfunction of wave equation) of the MHD oscillations are categorized into sausage, kink, helical kink, and fluting modes. Exact recognition of the wave functions and the frequencies of oscillations can be used in coronal seismology and also helps to the future high-resolution instruments that would be designed for studying the properties of the solar loop oscillations in details. The properties of collective oscillations of nonidentical and identical system of flux tubes and their interactions are studied. The ratios of frequencies, the oscillation frequencies of a system of flux tubes to their equivalent monolithic tube (ω sys/ω mono), are obtained between 0.748 and 0.841 for a system of nonidentical tubes, whereas the related ratios of frequencies for a system of identical flux tubes are fluctuated around 0.761.
Configuration interaction of hydropathic waves enables ubiquitin functionality
Allan, Douglas C.; Phillips, J. C.
2018-02-01
Ubiquitin, discovered less than 50 years ago, tags thousands of diseased proteins for destruction. It is small (only 76 amino acids), and is found unchanged in mammals, birds, fish and even worms. Key features of its functionality are identified here using critical point thermodynamic scaling theory. These include Fano interference between first- and second-order elements of correlated long-range globular surface shape transitions. Comparison with its closest relative, 76 amino acid Nedd8, shows that the latter lacks these features. A cracked elastic network model is proposed for the common target shared by many diseased proteins.
Best matching theory & applications
Moghaddam, Mohsen
2017-01-01
Mismatch or best match? This book demonstrates that best matching of individual entities to each other is essential to ensure smooth conduct and successful competitiveness in any distributed system, natural and artificial. Interactions must be optimized through best matching in planning and scheduling, enterprise network design, transportation and construction planning, recruitment, problem solving, selective assembly, team formation, sensor network design, and more. Fundamentals of best matching in distributed and collaborative systems are explained by providing: § Methodical analysis of various multidimensional best matching processes § Comprehensive taxonomy, comparing different best matching problems and processes § Systematic identification of systems’ hierarchy, nature of interactions, and distribution of decision-making and control functions § Practical formulation of solutions based on a library of best matching algorithms and protocols, ready for direct applications and apps development. Design...
Functional data analytic approach of modeling ECG T-wave shape to measure cardiovascular behavior
Zhou, Yingchun; 10.1214/09-AOAS273
2010-01-01
The T-wave of an electrocardiogram (ECG) represents the ventricular repolarization that is critical in restoration of the heart muscle to a pre-contractile state prior to the next beat. Alterations in the T-wave reflect various cardiac conditions; and links between abnormal (prolonged) ventricular repolarization and malignant arrhythmias have been documented. Cardiac safety testing prior to approval of any new drug currently relies on two points of the ECG waveform: onset of the Q-wave and termination of the T-wave; and only a few beats are measured. Using functional data analysis, a statistical approach extracts a common shape for each subject (reference curve) from a sequence of beats, and then models the deviation of each curve in the sequence from that reference curve as a four-dimensional vector. The representation can be used to distinguish differences between beats or to model shape changes in a subject's T-wave over time. This model provides physically interpretable parameters characterizing T-wave sh...
Functional connectivity between brain areas estimated by analysis of gamma waves.
Kheiri, Farshad; Bragin, Anatol; Engel, Jerome
2013-04-15
The goal of this study is to investigate functional connectivity between different brain regions by analyzing the temporal relationship of the maxima of gamma waves recorded in multiple brain areas. Local field potentials were recorded from motor cortex, hippocampus, entorhinal cortex and piriform cortex of rats. Gamma activity was filtered and separated into two bands; high (65-90Hz) and low (30-55Hz) gamma. Maxima for gamma activity waves were detected and functional connectivity between different brain regions was determined using Shannon entropy for perievent histograms for each pair channels. Significant Shannon entropy values were reported as connectivity factors. We defined a connectivity matrix based the connectivity factors between different regions. We found that maxima of low and high frequency gamma occur in strong temporal relationship between some brain areas, indicating the existence of functional connections between these areas. The spatial pattern of functional connections between brain areas was different for slow wave sleep and waking states. However for each behavioral state in the same animal the pattern of functional connections was stable over time within 30min of continuous analysis and over a 5 day period. With the same electrode montage the pattern of functional connectivity varied from one subject to another. Analysis of the temporal relationship of maxima of gamma waves between various brain areas could be a useful tool for investigation of functional connections between these brain areas. This approach could be applied for analysis of functional alterations occurring in these connections during different behavioral tasks and during processes related to learning and memory. The specificity in the connectivity pattern from one subject to another can be explained by the existence of unique functional networks for each subject. Copyright © 2013 Elsevier B.V. All rights reserved.
Do the generalized Fock-state wave functions have some relations ...
Indian Academy of Sciences (India)
Jeong Ryeol Choi et al the theory of quantum mechanics is introduced due to the comparative differences between the classical and quantum descriptions of physical systems [14]. In this paper, we shall investigate whether the generalized Fock-state wave functions have some relations with CIC for mechanical systems.
Influence of wetting layer wave functions on carrier capture in quantum dots
DEFF Research Database (Denmark)
Kristensen, Philip Trøst; Markussen, Troels; Tromborg, Bjarne
2005-01-01
This work numerically solves the effective mass Schrodinger equation and shows that the capture times are strongly influenced by details of the continuum states not accounted for by the approximate wave functions. Results show that calculations of capture time for phonon mediated carrier capture...
Fracchia, F.; Filippi, Claudia; Amovilli, C.
2012-01-01
We propose a new class of multideterminantal Jastrow–Slater wave functions constructed with localized orbitals and designed to describe complex potential energy surfaces of molecular systems for use in quantum Monte Carlo (QMC). Inspired by the generalized valence bond formalism, we elaborate a
On the excited state wave functions of Dirac fermions in the random ...
Indian Academy of Sciences (India)
In the last decade, it was shown that the Liouville field theory is an effective theory of Dirac fermions in the random gauge potential (FRGP). We show that the Dirac wave functions in FRGP can be written in terms of descendents of the Liouville vertex operator. In the quasiclassical approximation of the Liouville theory, our ...
Frequency-Domain Green's Functions for Radar Waves in Heterogeneous 2.5D Media
Green’s functions for radar waves propagating in heterogeneous media may be calculated in the frequency domain using a hybrid of two numerical methods. The model is defined in the Cartesian coordinate system, and its electromagnetic properties may vary in the x and z directions, ...
Three-Dimensional Visualization of Wave Functions for Rotating Molecule: Plot of Spherical Harmonics
Nagaoka, Shin-ichi; Teramae, Hiroyuki; Nagashima, Umpei
2013-01-01
At an early stage of learning quantum chemistry, undergraduate students usually encounter the concepts of the particle in a box, the harmonic oscillator, and then the particle on a sphere. Rotational levels of a diatomic molecule can be well approximated by the energy levels of the particle on a sphere. Wave functions for the particle in a…
Propriety of Approximation for Calculations of Nuclear Matrix Elements by Woods-Saxon Wave Functions
Utamuratov, R K; Nasirov, A K
2005-01-01
Single-particle matrix elements of nucleon transfer were calculated by Woods--Saxon potential wave functions and results are compared with ones calculated by spherical well approximation. The application of the approximation of the mean-field of nuclei at heavy-ion collisions by the spherical well, which is widely used in the model based on dinuclear concept, is proved.
Gilbert, Kenneth E
2015-01-01
The original formulation of the Green's function parabolic equation (GFPE) can have numerical accuracy problems for large normalized surface impedances. To solve the accuracy problem, an improved form of the GFPE has been developed. The improved GFPE formulation is similar to the original formulation, but it has the surface-wave pole "subtracted." The improved GFPE is shown to be accurate for surface impedances varying over 2 orders of magnitude, with the largest having a magnitude exceeding 1000. Also, the improved formulation is slightly faster than the original formulation because the surface-wave component does not have to be computed separately.
Yordanova, Juliana; Kirov, Roumen; Verleger, Rolf; Kolev, Vasil
2017-11-03
Co-existent sleep spindles and slow waves have been viewed as a mechanism for offline information processing. Here we explored if the temporal synchronization between slow waves and spindle activity during slow wave sleep (SWS) in humans was modulated by preceding functional activations during pre-sleep learning. We activated differentially the left and right hemisphere before sleep by using a lateralized variant of serial response time task (SRTT) and verified these inter-hemispheric differences by analysing alpha and beta electroencephalographic (EEG) activities during learning. The stability and timing of coupling between positive and negative phases of slow waves and sleep spindle activity during SWS were quantified. Spindle activity was temporally synchronized with both positive (up-state) and negative (down-state) slow half waves. Synchronization of only the fast spindle activity was laterally asymmetric after learning, corresponding to hemisphere-specific activations before sleep. However, the down state was associated with decoupling, whereas the up-state was associated with increased coupling of fast spindle activity over the pre-activated hemisphere. These observations provide original evidence that (1) the temporal grouping of fast spindles by slow waves is a dynamic property of human SWS modulated by functional pre-sleep activation patterns, and (2) fast spindles synchronized by slow waves are functionally distinct.
Job Searchers, Job Matches and the Elasticity of Matching
Broersma, L.; Ours, J.C. van
1998-01-01
This paper stresses the importance of a specification of the matching function in which the measure of job matches corresponds to the measure of job searchers. In many empirical studies on the matching function this requirement has not been fulfilled because it is difficult to find information about employed job searchers and job searchers from outside the labour market. In this paper, we specify and estimate matching functions where the flow corresponds to the correct stock. We use several a...
Wave based analysis of the Green's function for a layered cylindrical shell.
Magliula, Elizabeth A; McDaniel, J Gregory
2012-07-01
Cylindrical shells composed of concentric layers may be designed to affect the way that elastic waves are generated and propagated, particularly when some layers are anisotropic. To aid the design process, the present work develops a wave based analysis of the Green's function for a layered cylindrical shell in which the response is given as a sum of waves propagating in the axial coordinate. The analysis assumes linear Hookean materials for each layer. It uses finite element discretizations in the radial coordinate and Fourier series expansions in the circumferential coordinate, leading to linear equations in the axial wavenumber domain that relate shell displacements and forces. Inversion to the axial domain is accomplished via a state-space formulation that is evaluated using residue integration. The resulting expression for the Green's function for each circumferential harmonic is a summation over the natural waves of the shell. The finite element discretization in the radial direction allows the approach to be used for arbitrarily thick shells. The approach is benchmarked to results from an isotropic shell and numerical examples are given for a shell composed of a fiber-reinforced material. The numerical examples illustrate the effect of fiber orientation on the Green's function.
Computing Optimal Morse Matchings
Joswig, Michael; Pfetsch, Marc E.
2004-01-01
Morse matchings capture the essential structural information of discrete Morse functions. We show that computing optimal Morse matchings is NP-hard and give an integer programming formulation for the problem. Then we present polyhedral results for the corresponding polytope and report on computational results.
A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind
Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.;
2016-01-01
We use audification of 0.092 seconds cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes greater than 0.1 nanoteslas near the ion gyrofrequency (approximately 0.1 hertz) with duration longer than 1 hour during 2008. We present one of the most common types of event for a case study and find it to be a proton-cyclotron wave storm, coinciding with highly radial magnetic field and a suprathermal proton beam close in density to the core distribution itself. Using linear Vlasov analysis, we conclude that the long-duration, large-amplitude waves are generated by the instability of the proton distribution function. The origin of the beam is unknown, but the radial field period is found in the trailing edge of a fast solar wind stream and resembles other events thought to be caused by magnetic field footpoint motion or interchange reconnection between coronal holes and closed field lines in the corona.
Heavy quark fragmentation functions for D-wave quarkonium and charmed beauty mesons
Energy Technology Data Exchange (ETDEWEB)
Cheung, K. [Texas Univ., Austin, TX (United States). Center for Particle Physics; Yuan, T.C. [Univ. of California, Davis, CA (United States). Davis Inst. for High Energy Physics
1995-09-01
At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and {anti b}c mesons in high energy e{sup +}e{sup {minus}} and hadronic collisions is dominated by parton fragmentation. The authors calculate the heavy quark fragmentation functions into the D-wave quarkonium and {anti b}c mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the {anti b}c meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a {anti b} antiquark to split into the D-wave {anti b}c mesons is about 2 {times} 10{sup {minus}5}, which implies that only 2% of the total pseudo-scalar ground state B{sub c} comes from the cascades of these orbitally excited states.
Trend Extraction in Functional Data of Amplitudes of R and T Waves in Exercise Electrocardiogram
Cammarota, Camillo; Curione, Mario
The amplitudes of R and T waves of the electrocardiogram (ECG) recorded during the exercise test show both large inter- and intra-individual variability in response to stress. We analyze a dataset of 65 normal subjects undergoing ambulatory test. We model the dataset of R and T series in the framework of functional data, assuming that the individual series are realizations of a non-stationary process, centered at the population trend. We test the time variability of this trend computing a simultaneous confidence band and the zero crossing of its derivative. The analysis shows that the amplitudes of the R and T waves have opposite responses to stress, consisting respectively in a bump and a dip at the early recovery stage. Our findings support the existence of a relationship between R and T wave amplitudes and respectively diastolic and systolic ventricular volumes.
Mehrkash, Milad; Azhari, Mojtaba; Mirdamadi, Hamid Reza
2014-01-01
The importance of elastic wave propagation problem in plates arises from the application of ultrasonic elastic waves in non-destructive evaluation of plate-like structures. However, precise study and analysis of acoustic guided waves especially in non-homogeneous waveguides such as functionally graded plates are so complicated that exact elastodynamic methods are rarely employed in practical applications. Thus, the simple approximate plate theories have attracted much interest for the calculation of wave fields in FGM plates. Therefore, in the current research, the classical plate theory (CPT), first-order shear deformation theory (FSDT) and third-order shear deformation theory (TSDT) are used to obtain the transient responses of flexural waves in FGM plates subjected to transverse impulsive loadings. Moreover, comparing the results with those based on a well recognized hybrid numerical method (HNM), we examine the accuracy of the plate theories for several plates of various thicknesses under excitations of different frequencies. The material properties of the plate are assumed to vary across the plate thickness according to a simple power-law distribution in terms of volume fractions of constituents. In all analyses, spatial Fourier transform together with modal analysis are applied to compute displacement responses of the plates. A comparison of the results demonstrates the reliability ranges of the approximate plate theories for elastic wave propagation analysis in FGM plates. Furthermore, based on various examples, it is shown that whenever the plate theories are used within the appropriate ranges of plate thickness and frequency content, solution process in wave number-time domain based on modal analysis approach is not only sufficient but also efficient for finding the transient waveforms in FGM plates. Copyright © 2013 Elsevier B.V. All rights reserved.
Snyder, D
2002-01-01
A straightforward explanation of fundamental tenets of quantum mechanics concerning the wave function results in the thesis that the quantum mechanical wave function is a link between human cognition and the physical world. The reticence on the part of physicists to adopt this thesis is discussed. A comparison is made to the behaviorists' consideration of mind, and the historical roots of how the problem concerning the quantum mechanical wave function arose are discussed. The basis for an empirical demonstration that the wave function is a link between human cognition and the physical world is provided through developing an experiment using methodology from psychology and physics. Based on research in psychology and physics that relied on this methodology, it is likely that Einstein, Podolsky, and Rosen's theoretical result that mutually exclusive wave functions can simultaneously apply to the same concrete physical circumstances can be implemented on an empirical level.
Majorana wave-function oscillations, fermion parity switches, and disorder in Kitaev chains
Hegde, Suraj S.; Vishveshwara, Smitha
2016-09-01
We study the decay and oscillations of Majorana fermion wave functions and ground-state (GS) fermion parity in one-dimensional topological superconducting lattice systems. Using a Majorana transfer matrix method, we find that Majorana wave-function properties are encoded in the associated Lyapunov exponent, which in turn is the sum of two independent components: a "superconducting component," which characterizes the gap induced decay, and the "normal component," which determines the oscillations and response to chemical potential configurations. The topological phase transition separating phases with and without Majorana end modes is seen to be a cancellation of these two components. We show that Majorana wave-function oscillations are completely determined by an underlying nonsuperconducting tight-binding model and are solely responsible for GS fermion parity switches in finite-sized systems. These observations enable us to analytically chart out wave-function oscillations, the resultant GS parity configuration as a function of parameter space in uniform wires, and special parity switch points where degenerate zero energy Majorana modes are restored in spite of finite size effects. For disordered wires, we find that band oscillations are completely washed out leading to a second localization length for the Majorana mode and the remnant oscillations are randomized as per Anderson localization physics in normal systems. Our transfer matrix method further allows us to (i) reproduce known results on the scaling of midgap Majorana states and demonstrate the origin of its log-normal distribution, (ii) identify contrasting behavior of disorder-dependent GS parity switches for the cases of even versus odd number of lattice sites, and (iii) chart out the GS parity configuration and associated parity switch points as a function of disorder strength.
Job Searchers, Job Matches and the Elasticity of Matching
Broersma, L.; van Ours, J.C.
1998-01-01
This paper stresses the importance of a specification of the matching function in which the measure of job matches corresponds to the measure of job searchers. In many empirical studies on the matching function this requirement has not been fulfilled because it is difficult to find information about
Non-dipolar Wilson links for transverse-momentum-dependent wave functions
Energy Technology Data Exchange (ETDEWEB)
Li, Hsiang-nan [Institute of Physics, Academia Sinica,Taipei, Taiwan 115 (China); Department of Physics, National Cheng-Kung University,Tainan, Taiwan 701 (China); Department of Physics, National Tsing-Hua University,Hsinchu, Taiwan 300 (China); Wang, Yu-Ming [Institut für Theoretische Teilchenphysik und Kosmologie RWTH Aachen,D-52056 Aachen (Germany); Physik Department T31, James-Franck-Straße, Technische Universität München,D-85748 Garching (Germany)
2015-06-03
We propose a new definition of a transverse-momentum-dependent (TMD) wave function with simpler soft subtraction for k{sub T} factorization of hard exclusive processes. The un-subtracted wave function involves two pieces of non-light-like Wilson links oriented in different directions, so that the rapidity singularity appearing in usual k{sub T} factorization is regularized, and the pinched singularity from Wilson-link self-energy corrections is alleviated to a logarithmic one. In particular no soft function is needed, when the two pieces of Wilson links are orthogonal to each other. We show explicitly at one-loop level that the simpler definition with the non-dipolar Wilson links exhibits the same infrared behavior as the one with the dipolar Wilson links and complicated soft subtraction. It is pointed out that both definitions reduce to the naive TMD wave function as the non-light-like Wilson links approach to the light cone. Their equivalence is then extended to all orders by considering the evolution in the Wilson-link rapidity.
Peach, Robert C
2009-10-01
The Green's function or boundary element method (BEM) is the best available technique for rigorous surface acoustic wave (SAW) device analysis. However, its computational cost usually means that it cannot be applied directly to devices with complex, nonperiodic electrode structures. In this paper, approximate forms for the Green's function are employed. They are based on rigorous representations, they can represent the Green's function to any required degree of accuracy, and they can be applied to any type of substrate and acoustic wave. The use of this type of approximation for practical device analysis is considered, and computational procedures are presented that can exploit the special approximate Green's function structure. It is shown that highly efficient computational algorithms can be constructed, in which the computational effort increases linearly with the number of electrodes in the device. These methods can be applied to any type of device structure, and they do not require any empirically derived parameters. The practical application of the methods is illustrated by examples of longitudinally coupled resonator filter (LCRF) designs implemented using leaky wave cuts of lithium tantalate. Agreement between theory and experiment is excellent, even for devices of this complexity.
Lin, Keh-chung; Wang, Tien-ni; Wu, Ching-yi; Chen, Chia-ling; Chang, Kai-chieh; Lin, Yu-chan; Chen, Yi-ju
2011-01-01
This study compared home-based constraint-induced therapy (CIT) with a dose-matched home-based control intervention for children with cerebral palsy (CP). The differences in unilateral and bilateral motor performance, daily functions, and quality of parental well-being (i.e., the stress level of their parents) were evaluated. The study included 21…
Form Factors and Wave Functions of Vector Mesons in Holographic QCD
Energy Technology Data Exchange (ETDEWEB)
Hovhannes R. Grigoryan; Anatoly V. Radyushkin
2007-07-01
Within the framework of a holographic dual model of QCD, we develop a formalism for calculating form factors of vector mesons. We show that the holographic bound states can be described not only in terms of eigenfunctions of the equation of motion, but also in terms of conjugate wave functions that are close analogues of quantum-mechanical bound state wave functions. We derive a generalized VMD representation for form factors, and find a very specific VMD pattern, in which form factors are essentially given by contributions due to the first two bound states in the Q^2-channel. We calculate electric radius of the \\rho-meson, finding the value < r_\\rho^2>_C = 0.53 fm^2.
High energy QCD at NLO: from light-cone wave function to JIMWLK evolution
Lublinsky, Michael; Mulian, Yair
2017-05-01
Soft components of the light cone wave-function of a fast moving projectile hadron is computed in perturbation theory to the third order in QCD coupling constant. At this order, the Fock space of the soft modes consists of one-gluon, two-gluon, and a quark-antiquark states. The hard component of the wave-function acts as a non-Abelian background field for the soft modes and is represented by a valence charge distribution that accounts for non-linear density effects in the projectile. When scattered off a dense target, the diagonal element of the S-matrix reveals the Hamiltonian of high energy evolution, the JIMWLK Hamiltonian. This way we provide a new direct derivation of the JIMWLK Hamiltonian at the Next-to-Leading Order.
Time-dependent density-functional theory in the projector augmented-wave method
DEFF Research Database (Denmark)
Walter, Michael; Häkkinen, Hannu; Lehtovaara, Lauri
2008-01-01
We present the implementation of the time-dependent density-functional theory both in linear-response and in time-propagation formalisms using the projector augmented-wave method in real-space grids. The two technically very different methods are compared in the linear-response regime where we...... surfaces for a set of atoms and molecules with the linear-response method and by calculating nonlinear emission spectra using the time-propagation method....
On the excited state wave functions of Dirac fermions in the random ...
Indian Academy of Sciences (India)
In the RMT approach, the distribution functions for the wave func- tions' amplitude (i.e. p(t)) are derived by means of RMT. It depends only on the global symmetry of the ensemble and has a chi-square form. The asymptotic form of p(t) in 2D samples for L ≪ ξ was found using the renormalization group and replica techniques ...
Two Variations On The Theme Of The Wave Function Of The Universe
Nitti, F
2005-01-01
In this work, we analyze two different aspects of the formulation of Quantum Gravity using the Wave Function of the Universe approach. In Part I we search for a way to define nonperturbatively the wave function, in the context of gravity in 2+1 dimensions, making use of the conjectured duality between the latter and 2-d conformal field theory on the spacetime boundary. In the pure gravity case, it has been known that the Wheeler-DeWitt equation, that formally defines the wave function, can be interpreted as a Ward identity for the boundary theory, which in this case can be identified with a model with affine sl(2, R) invariance. We try to extend this method to the general case when gravity is coupled to matter. What makes this possible is our finding that there exist a boundary affine sl(2, R) algebra structure also in the most general case: any two dimensional conformal field theory can be universally embedded into a larger structure that carries an action for that algebra. Part II has a more phenomenologica...
Busch, Thilo; Esposti, Alessandra Degli; Werner, Hans-Joachim
1991-05-01
A method to calculate analytical energy gradients for multiconfiguration self-consistent field (MCSCF) wave functions with frozen core orbitals is presented. Since the core orbitals, which are taken from a closed shell SCF calculation, are not variationally optimized in the MCSCF procedure, it is necessary to determine their derivatives by solving a set of coupled perturbed Hartree-Fock (CPHF) equations. The technique is similar to the calculation of energy gradients for CI wave functions, but is complicated by the fact that the SCF and MCSCF orbitals are different. This makes it necessary to perform a transformation between the two orbital basis sets at an intermediate stage. The CPHF equations are solved by an iterative method, in which optionally part of the Hessian matrix can be constructed and inverted explicitly. Some applications of the method are presented. For the molecule P2S, optimized geometries for two isomers and a saddle point are compared for MCSCF wave functions with frozen and fully optimized core orbitals. It is demonstrated that in both cases virtually identical results are obtained and that the frozen-core approximation leads to significant savings in computer time. Some preliminary results are also reported for tetrasilabicyclo[1.1.0]butane, Si4H6.
Lee, Ji-Hyun; Lee, Sangyong; Choi, SeokJoo; Choi, Yoon-Hee; Lee, Kwansub
2017-01-01
[Purpose] The purpose of this study was to identify the effects of extracorporeal shock wave therapy on the pain and function of patients with degenerative knee arthritis. [Subjects and Methods] Twenty patients with degenerative knee arthritis were divided into a conservative physical therapy group (n=10) and an extracorporeal shock wave therapy group (n=10). Both groups received general conservative physical therapy, and the extracorporeal shock wave therapy was additionally treated with ext...
Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions.
Cavalcanti-Galdino, M K; Silva, J A da; Mendes, L C; Santos, N A da; Simas, M L B
2014-04-01
The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF) for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and no history of alcoholism were enrolled in two experimental groups: 1) no alcohol intake (control group) and 2) alcohol ingestion (experimental group). The average concentration of alcohol in the experimental group was set to about 0.08%. We used a paradigm involving a forced-choice method. Maximum sensitivity to contrast for sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24 and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast sensitivity were observed after alcohol intake compared with the control condition at spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at maximum sensitivity and at the low and high frequency ends for angular frequency stimuli, both under photopic luminance conditions.
Mitri, Farid
2014-11-01
The generalized theory of resonance scattering (GTRS) by an elastic spherical target in acoustics is extended to describe the arbitrary scattering of a finite beam using the addition theorem for the spherical wave functions of the first kind under a translation of the coordinate origin. The advantage of the proposed method over the standard discrete spherical harmonics transform previously used in the GTRS formalism is the computation of the off-axial beam-shape coefficients (BSCs) stemming from a closed-form partial-wave series expansion representing the axial BSCs in spherical coordinates. With this general method, the arbitrary acoustical scattering can be evaluated for any particle shape and size, whether the particle is partially or completely illuminated by the incident beam. Numerical examples for the axial and off-axial resonance scattering from an elastic sphere placed arbitrarily in the field of a finite circular piston transducer with uniform vibration are provided. Moreover, the 3-D resonance directivity patterns illustrate the theory and reveal some properties of the scattering. Numerous applications involving the scattering phenomenon in imaging, particle manipulation, and the characterization of multiphase flows can benefit from the present analysis because all physically realizable beams radiate acoustical waves from finite transducers as opposed to waves of infinite extent.
Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions
Directory of Open Access Journals (Sweden)
M.K. Cavalcanti-Galdino
2014-04-01
Full Text Available The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and no history of alcoholism were enrolled in two experimental groups: 1 no alcohol intake (control group and 2 alcohol ingestion (experimental group. The average concentration of alcohol in the experimental group was set to about 0.08%. We used a paradigm involving a forced-choice method. Maximum sensitivity to contrast for sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24 and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast sensitivity were observed after alcohol intake compared with the control condition at spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at maximum sensitivity and at the low and high frequency ends for angular frequency stimuli, both under photopic luminance conditions.
Tamaru, S.; Bain, J. A.; Kryder, M. H.; Ricketts, D. S.
2011-08-01
This paper presents the two-dimensional (2D) Green’s function (GF) of magnetostatic surface waves (MSSWs) in real space and the frequency domain, i.e., the spatial propagation pattern of MSSWs emitted by a point wave source in a tangentially magnetized slab geometry, including the effect of finite damping. The theory first derives an inhomogeneous differential equation of the spin system under a magnetostatic approximation. This equation is translated into a Sturm-Liouville problem by introducing a Hermitian operator, and solved by the eigenfunction expansion technique, which yields an integral expression of the GF in the form of a 2D inverse Fourier transform. The obtained GF demonstrates various features characteristic of MSSWs, such as strongly anisotropic propagation, angular confinement of energy flow from the wave source whose limit angle is defined as the critical angle for the group velocity θg, and semicaustic beams along θg. We then calculate the 1D spatial profiles and 2D diffraction patterns of MSSW propagation by convolving the GF with various wave source distributions, and compare them with experimental results observed on a tangentially magnetized Permalloy film. Comparison between these numerical and experimental results shows excellent agreement.
Energy Technology Data Exchange (ETDEWEB)
Feuerstein, B.; Moshammer, R.; Ullrich, J. [Freiburg Univ. (Germany); Schulz, M
2001-07-01
Recently, a new method of analysing electron correlations based on intensity interferometry has been applied to double ionization of He and Ne by fast ion impact [1]. The data reveal sensitively correlation effects while they appear to be very insensitive to the collision dynamics. In order to analyse the role of the initial state electron correlation a statistically defined correlation function based on intensity interferometry was calculated for the ground state of He. In a comparative study of model wave functions we demonstrate that correlation can be considered from a statistical point of view which offers a new tool to study correlation effects in many-particle systems. (orig.)
Feuerstein, B.; Schulz, M.; Moshammer, R.; Ullrich, J.
Recently, a new method of analysing electron correlations based on intensity interferometry has been applied to double ionization of He and Ne by fast ion impact [1]. The data reveal sensitively correlation effects while they appear to be very insensitive to the collision dynamics. In order to analyse the role of the initial state electron correlation a statistically defined correlation function based on intensity interferometry was calculated for the ground state of He. In a comparative study of model wave functions we demonstrate that correlation can be considered from a statistical point of view which offers a new tool to study correlation effects in many-particle systems.
The s-Wave Neutron Strength Function in the Deformed Region
Izumi, FURUOYA; Ryuzo, NAKASIMA; Department of Physics, Hosei University
1983-01-01
The effect of the doorway states on the s-wave neutron strength function of the deformed nucleus is examined. It is found that the shape of the 4-s giant resonance in the strength function is reproduced fairly well by both effects of the doorway states and the coupled channels. In particular, the irregular hump ranging from A=160 to A=170 cannot be interpreted by coupled channel calculation alone but by additional effect of the doorway states. As an example of the isotopic trend, the numerica...
Approximate Green's function representations for the analysis of SAW and leaky wave devices.
Peach, Robert C
2009-10-01
The Green's function or boundary element method (BEM) is the preferred technique for rigorous SAW device analysis. However, because of its computational cost, its principal application is the analysis of mode propagation in periodic structures to determine parameters that can then be used in simplified coupling of modes (COM) or P-matrix models. In this paper, rigorous representations are derived that express the Green's function in terms of a continuous superposition of modes. The derivations include detailed analysis of the Green's function properties as a function of both frequency and wavenumber, and representations are obtained for both the slowness and spatial domains. Approximate forms are then generated by replacing the continuous mode superposition by a discrete one. The Green's function can be approximated to any required degree of accuracy, and the resulting approximations are applicable to any type of wave on any type of substrate. The long-range spatial components in the approximate forms are represented by exponential terms. The separable properties of these terms allow this class of approximation to be applied to general SAW and leaky wave device analysis in such a way that the computational effort increases only linearly with device size.
Roshchina, G Ia; Koroleva, V I; Davydov, V I
2012-01-01
EEG aftereffects of spreading depression waves were studied in waking rabbits in chronic experiments by spectral coherence analysis. Experiments were divided in two groups: early (from the first to the third-fourth experiments) and late (fifth-tenth experiments). During the early experimental series, unilateral persistent EEG changes consisting in an increase in the delta- and beta-band power with a simultaneous depression of the gamma-band activity were observed in the ipsilateral to SD hemisphere. In addition, interhemispheric coherence between symmetrical cortical points decreased. During the late experimental series, a generalized bilateral increase in the power of the delta and beta activity was demonstrated with a rise in coherence in the beta band. This generalized activity occurred cyclically and was distinct during a long period of time (2-3 hours) after propagation of a single SD wave. Such kind of cyclical activity blocked the propagation of subsequent SD waves in the neocortex of a waking rabbit and decreased the probability of recurrent wave origin up to a complete cessation of wave generation. Thus, a cortical SD wave provoked the appearance of synchronized beta oscillations in the EEG, which in turn actively influenced the properties of recurrent waves.
Stochastic piecewise linear function fitting with application to ultrasound shear wave imaging.
Ingle, Atul; Varghese, Tomy; Sethares, William; Bucklew, James
2014-01-01
Piecewise linear function fitting is ubiquitous in many signal processing applications. Inspired by an application to shear wave velocity imaging in ultrasound elastography, this paper presents a discrete state-space Markov model for noisy piecewise linear data and also proposes a tractable algorithm for maximum a posteriori estimation of the slope of each segment in the piecewise linear function. The number and locations of breaks is handled indirectly by the stochastics of the Markov model. In the ultrasound shear wave imaging application, these slope values have concrete physical interpretation as being the reciprocal of the shear wave velocities in the imaged medium. Data acquired on an ellipsoidal inclusion phantom shows that this algorithm can provide good contrast of around 6 dB and contrast to noise ratio of 25 dB between the stiff inclusion and surrounding soft background. The phantom validation study also shows that this algorithm can be used to preserve sharp boundary details, which would otherwise be blurred out if a sliding window least squares filter is applied.
Blast Wave Dynamics at the Cornea as a Function of Eye Protection Form and Fit.
Williams, Steven T; Harding, Thomas H; Statz, J Keegan; Martin, John S
2017-03-01
A shock tube and anthropomorphic headforms were used to investigate eye protection form and fit using eyewear on the Authorized Protective Eyewear List in primary ocular blast trauma experiments. Time pressure recordings were obtained from highly linear pressure sensors mounted at the cornea of instrumented headforms of different sizes. A custom shock tube produced highly reliable shock waves and pressure recordings were collected as a function of shock wave orientation and protective eyewear. Eyewear protection coefficients were calculated as a function of a new metric of eyewear fit. In general, better protection was correlated with smaller gaps between the eyewear and face. For oblique angles, most spectacles actually potentiated the blast wave by creating higher peak pressures at the cornea. Installing foam around the perimeter of the spectacle lens to close the gap between the lens and face resulted in significantly lower pressure at the cornea. In conclusion, current eye protection, which was designed to reduce secondary and tertiary blast injuries, provides insufficient protection against primary blast injury. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.
Rayleigh wave behavior in functionally graded magneto-electro-elastic material
Ezzin, Hamdi; Mkaoir, Mohamed; Amor, Morched Ben
2017-12-01
Piezoelectric-piezomagnetic functionally graded materials, with a gradual change of the mechanical and electromagnetic properties have greatly applying promises. Based on the ordinary differential equation and stiffness matrix methods, a dynamic solution is presented for the propagation of the wave on a semi-infinite piezomagnetic substrate covered with a functionally graded piezoelectric material (FGPM) layer. The materials properties are assumed to vary in the direction of the thickness according to a known variation law. The phase and group velocity of the Rayleigh wave is numerically calculated for the magneto-electrically open and short cases, respectively. The effect of gradient coefficients on the phase velocity, group velocity, coupled magneto-electromechanical factor, on the stress fields, the magnetic potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the hetero-structure PZT-5A/CoFe2O4; the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Rayleigh wave propagation behavior.
Shen, Xiaoqin; Ren, Dawei; Cao, Xiaoshan; Wang, Ji
2017-11-06
In this study, cut-off frequencies of the circumferential SH waves in functionally graded piezoelectric-piezomagnetic material (FGPPM) cylinder shells with traction free, electrical and magnetic open boundary conditions are investigated analytically. The Wentzel-Kramers-Brillouin (WKB) method is employed for solving differential equations with variable coefficients for general cases. For comparison, Bessel functions and Kummer functions are used for solving cut-off frequency problems in homogenous and ideal FGPPM cylinder shells. It is shown that the WKB solution for the cut-off frequencies has good precise. The set of cut-off frequencies is a series of approximate arithmetic progressions, for which the difference is a function of the density and the effective elastic parameter. The relationship between the difference and the gradient coefficient is described. These results provide theoretical guidance for the non-destructive evaluation of curved shells based on the cut-off frequencies. Copyright © 2017 Elsevier B.V. All rights reserved.
Surface Acoustic Wave (SAW-Enhanced Chemical Functionalization of Gold Films
Directory of Open Access Journals (Sweden)
Gina Greco
2017-10-01
Full Text Available Surface chemical and biochemical functionalization is a fundamental process that is widely applied in many fields to add new functions, features, or capabilities to a material’s surface. Here, we demonstrate that surface acoustic waves (SAWs can enhance the chemical functionalization of gold films. This is shown by using an integrated biochip composed by a microfluidic channel coupled to a surface plasmon resonance (SPR readout system and by monitoring the adhesion of biotin-thiol on the gold SPR areas in different conditions. In the case of SAW-induced streaming, the functionalization efficiency is improved ≈ 5 times with respect to the case without SAWs. The technology here proposed can be easily applied to a wide variety of biological systems (e.g., proteins, nucleic acids and devices (e.g., sensors, devices for cell cultures.
Linear-scaling density functional theory using the projector augmented wave method
Hine, Nicholas D. M.
2017-01-01
Quantum mechanical simulation of realistic models of nanostructured systems, such as nanocrystals and crystalline interfaces, demands computational methods combining high-accuracy with low-order scaling with system size. Blöchl’s projector augmented wave (PAW) approach enables all-electron (AE) calculations with the efficiency and systematic accuracy of plane-wave pseudopotential calculations. Meanwhile, linear-scaling (LS) approaches to density functional theory (DFT) allow for simulation of thousands of atoms in feasible computational effort. This article describes an adaptation of PAW for use in the LS-DFT framework provided by the ONETEP LS-DFT package. ONETEP uses optimisation of the density matrix through in situ-optimised local orbitals rather than the direct calculation of eigenstates as in traditional PAW approaches. The method is shown to be comparably accurate to both PAW and AE approaches and to exhibit improved convergence properties compared to norm-conserving pseudopotential methods.
Diehl, T.; Ammon, C. J.; Mejia, J.
2002-12-01
Despite substantial effort, some uncertainty in the bulk crustal geology beneath the Tibetan Plateau remains. Recent experiments have provided a wealth of seismic data for investigating structures within the Tibetan lithosphere. We investigate the subsurface Tibetan geology using receiver functions from the 1991-1992 Passive Source and the 1997-1999 INDEPTH III experiments. We have completed joint inversions of surface-wave dispersion and select receiver functions for the older data and plan to explore and invert receiver functions from select stations from the INDEPTH III experiment. The combination of receiver functions with surface-wave dispersion does much to improve P- and S-velocity structure resolution, but modeling is most appropriate for relatively simple structures. We begin our analyses with the depth-velocity stacking estimation of Zhu and Kanamori [2000] where we attempt to extract thickness, P-velocity, and Vp/Vs ratios compatible with the move-out of the Ps conversion and multiples from velocity contrasts within the lithosphere. Again, the main limitation of the technique is the assumption of a simple structure to insure consistency with a set of straightforward travel-time equations used to compute arrival-time move-out (as a function of incident-wave ray parameter). Poisson's ratio values from the 1991-1992 deployment were difficult to extract because of complex structure. The station with simplest response, WNDO, suggests a ratio of 0.28 beneath the north-central Plateau, which is slightly above average for continental crust. These results are lower than some earlier values which suggested that the lower crust beneath central and northern Tibet may contain substantial partial melt. The joint inversion of the simplest available receiver functions, and global long-period and local short-period surface-wave dispersion observations suggests that the crustal thickness for the northern Plateau ranges from 60-70 km (stations ERDO, BUDO, TUNL). Thickness
Directory of Open Access Journals (Sweden)
Joel Singer
Full Text Available OBJECTIVES: Pulse wave velocity (PWV is a measure of arterial stiffness and its increase with ageing has been associated with damage to cerebral microvessels and cognitive impairment. This study examined the relationship between carotid-femoral PWV and specific domains of cognitive function in a non-demented elderly sample. METHOD: Data were drawn from the Sydney Memory and Ageing Study, a cohort study of non-demented community-dwelling individuals aged 70-90 years, assessed in successive waves two years apart. In Wave 2, PWV and cognitive function were measured in 319 participants. Linear regression was used to analyse the cross-sectional relationship between arterial stiffness and cognitive function in the whole sample, and separately for men and women. Analysis of covariance was used to assess potential differences in cognition between subjects with PWV measurements in the top and bottom tertiles of the cohort. Covariates were age, education, body mass index, pulse rate, systolic blood pressure, cholesterol, depression, alcohol, smoking, hormone replacement therapy, apolipoprotein E ε4 genotype, use of anti-hypertensive medications, history of stroke, transient ischemic attack, myocardial infarction, angina, diabetes, and also sex for the whole sample analyses. RESULTS: There was no association between PWV and cognition after Bonferroni correction for multiple testing. When examining this association for males and females separately, an association was found in males, with higher PWV being associated with lower global cognition and memory, however, a significant difference between PWV and cognition between males and females was not found. CONCLUSION: A higher level of PWV was not associated with lower cognitive function in the whole sample.
Beshtoev, K M
2006-01-01
I have considered three-neutrino vacuum transitions and oscillations in the general case and obtained expressions for neutrino wave functions in three cases: with $CP$ violation, without $CP$ violation and in the case when direct $\
Lamb Waves in a Functionally Graded Composite Plate with Nonintegral Power Function Volume Fractions
National Research Council Canada - National Science Library
Cao, Xiaoshan; Qu, Zhen; Shi, Junping; Ru, Yan
2015-01-01
...) plate, which is a composite of two kinds of materials. The mechanical parameters depend on the volume fractions, which are nonintegral power functions, and the gradient coefficient is the power value...
Sensory function: insights from Wave 2 of the National Social Life, Health, and Aging Project.
Pinto, Jayant M; Kern, David W; Wroblewski, Kristen E; Chen, Rachel C; Schumm, L Philip; McClintock, Martha K
2014-11-01
Sensory function, a critical component of quality of life, generally declines with age and influences health, physical activity, and social function. Sensory measures collected in Wave 2 of the National Social Life, Health, and Aging Project (NSHAP) survey focused on the personal impact of sensory function in the home environment and included: subjective assessment of vision, hearing, and touch, information on relevant home conditions and social sequelae as well as an improved objective assessment of odor detection. Summary data were generated for each sensory category, stratified by age (62-90 years of age) and gender, with a focus on function in the home setting and the social consequences of sensory decrements in each modality. Among both men and women, older age was associated with self-reported impairment of vision, hearing, and pleasantness of light touch. Compared with women, men reported significantly worse hearing and found light touch less appealing. There were no gender differences for vision. Overall, hearing loss seemed to have a greater impact on social function than did visual impairment. Sensory function declines across age groups, with notable gender differences for hearing and light touch. Further analysis of sensory measures from NSHAP Wave 2 may provide important information on how sensory declines are related to health, social function, quality of life, morbidity, and mortality in this nationally representative sample of older adults. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Energy Technology Data Exchange (ETDEWEB)
Macia, R.; Correig, A.M.
1987-01-01
The medium through which seismic waves propagate acts as a filter. This filter is characterized by the medium spectral transfer functions, that deppend only on the model parameters that represents the medium. The behaviour of the ratio of amplitudes between spectral transfer functions, corresponding to vertical and horizontal desplacements of long period P-waves propagating though a stratified media, is analysed. Correlations between the properties of a theoretical model with respect to the curve defined by the ratio of the spectral transfer functions are studied as a function of frequency, as well as the influence of the parameters that define de model of the curves. Finally, the obtained correlations are analysed from the point of view of the utilisations to the study of the Earth's Crust. (Author)
Diverging probability-density functions for flat-top solitary waves
Peleg, Avner; Chung, Yeojin; Dohnal, Tomáš; Nguyen, Quan M.
2009-08-01
We investigate the statistics of flat-top solitary wave parameters in the presence of weak multiplicative dissipative disorder. We consider first propagation of solitary waves of the cubic-quintic nonlinear Schrödinger equation (CQNLSE) in the presence of disorder in the cubic nonlinear gain. We show by a perturbative analytic calculation and by Monte Carlo simulations that the probability-density function (PDF) of the amplitude η exhibits loglognormal divergence near the maximum possible amplitude ηm , a behavior that is similar to the one observed earlier for disorder in the linear gain [A. Peleg , Phys. Rev. E 72, 027203 (2005)]. We relate the loglognormal divergence of the amplitude PDF to the superexponential approach of η to ηm in the corresponding deterministic model with linear/nonlinear gain. Furthermore, for solitary waves of the derivative CQNLSE with weak disorder in the linear gain both the amplitude and the group velocity β become random. We therefore study analytically and by Monte Carlo simulations the PDF of the parameter p , where p=η/(1-ɛsβ/2) and ɛs is the self-steepening coefficient. Our analytic calculations and numerical simulations show that the PDF of p is loglognormally divergent near the maximum p value.
P-wave receiver function study of crustal structure in Scandinavia
Makushkina, Anna; Thybo, Hans; Vinnik, Lev; Youssof, Mohammad
2016-04-01
In this study we present preliminary results on the structure of the continental crust in northern Scandinavia. The research area consists of three geologically different domains: the Archaean Domain in the north-east, the Palaeoproterozoic Svecofennian Domain in the east and the Caledonian Deformed Domain in the west (Gorbatschev and Bogdanova,1993). We present results based on data collected by 60 seismic stations during 2-4 years of deployment in the ScanArray experiment, which is an international collaboration between Scandinavian, German and British universities. We use the receiver function (RF) technique in the LQT ray-oriented coordinate system (Vinnik, 1977). Receiver function analysis has rather high vertical resolution of the depth to seismic discontinuities which cause transformation between P- and S-waves. The whole dataset is uniformly filtered and deconvolved records are stacked using appropriate moveout corrections. We have used events with a magnitude ≥ 5.5 Mw, with epicentral distances range from 30° to 95°. The technique allows us to constrain crustal structure and determine the Moho depth around stations by analyzing the PS converted phases generated at discontinuities in particular the Moho. We present preliminary interpretation of P-wave RF analysis in terms of the complex tectonic and geodynamic evolution of the Baltic Shield. Further studies will include joint P and S receiver function analysis of this area as well as investigations of the upper mantle. References: Vinnik L.P. (1977) Detection of waves converted from P to SV in the mantle. Phys. Earth planet. Inter. 15, 39-45 Gorbatschev R., Bogdanova, S. (1993) Frontiers in the Baltic Shield. Precambrian Res. 64, 3-21
A correction function method for the wave equation with interface jump conditions
Abraham, David S.; Marques, Alexandre Noll; Nave, Jean-Christophe
2018-01-01
In this paper a novel method to solve the constant coefficient wave equation, subject to interface jump conditions, is presented. In general, such problems pose issues for standard finite difference solvers, as the inherent discontinuity in the solution results in erroneous derivative information wherever the stencils straddle the given interface. Here, however, the recently proposed Correction Function Method (CFM) is used, in which correction terms are computed from the interface conditions, and added to affected nodes to compensate for the discontinuity. In contrast to existing methods, these corrections are not simply defined at affected nodes, but rather generalized to a continuous function within a small region surrounding the interface. As a result, the correction function may be defined in terms of its own governing partial differential equation (PDE) which may be solved, in principle, to arbitrary order of accuracy. The resulting scheme is not only arbitrarily high order, but also robust, having already seen application to Poisson problems and the heat equation. By extending the CFM to this new class of PDEs, the treatment of wave interface discontinuities in homogeneous media becomes possible. This allows, for example, for the straightforward treatment of infinitesimal source terms and sharp boundaries, free of staircasing errors. Additionally, new modifications to the CFM are derived, allowing compatibility with explicit multi-step methods, such as Runge-Kutta (RK4), without a reduction in accuracy. These results are then verified through numerous numerical experiments in one and two spatial dimensions.
Mo, Yirong; Gao, Jiali; Peyerimhoff, Sigrid D.
2000-04-01
An energy decomposition scheme based on the block-localized wave function (BLW) method is proposed. The key of this scheme is the definition and the full optimization of the diabatic state wave function, where the charge transfer among interacting molecules is deactivated. The present energy decomposition (ED), BLW-ED, method is similar to the Morokuma decomposition scheme in definition of the energy terms, but differs in implementation and the computational algorithm. In addition, in the BLW-ED approach, the basis set superposition error is fully taken into account. The application of this scheme to the water dimer and the lithium cation-water clusters reveals that there is minimal charge transfer effect in hydrogen-bonded complexes. At the HF/aug-cc-PVTZ level, the electrostatic, polarization, and charge-transfer effects contribute 65%, 24%, and 11%, respectively, to the total bonding energy (-3.84 kcal/mol) in the water dimer. On the other hand, charge transfer effects are shown to be significant in Lewis acid-base complexes such as H3NSO3 and H3NBH3. In this work, the effect of basis sets used on the energy decomposition analysis is addressed and the results manifest that the present energy decomposition scheme is stable with a modest size of basis functions.
Paul, Jonathan D.; Eakin, Caroline M.
2017-07-01
Crustal receiver functions have been calculated from 128 events for two three-component broadband seismomenters located on the south coast (FOMA) and in the central High Plateaux (ABPO) of Madagascar. For each station, crustal thickness and V p / V s ratio were estimated from H- κ plots. Self-consistent receiver functions from a smaller back-azimuthal range were then selected, stacked and inverted to determine shear wave velocity structure as a function of depth. These results were corroborated by guided forward modeling and by Monte Carlo error analysis. The crust is found to be thinner (39 ± 0.7 km) beneath the highland center of Madagascar compared to the coast (44 ± 1.6 km), which is the opposite of what would be expected for crustal isostasy, suggesting that present-day long wavelength topography is maintained, at least in part, dynamically. This inference of dynamic support is corroborated by shear wave splitting analyses at the same stations, which produce an overwhelming majority of null results (>96 %), as expected for vertical mantle flow or asthenospheric upwelling beneath the island. These findings suggest a sub-plate origin for dynamic support.
Zero Field Splitting of the chalcogen diatomics using relativistic correlated wave-function methods
DEFF Research Database (Denmark)
Rota, Jean-Baptiste; Knecht, Stefan; Fleig, Timo
2011-01-01
The spectrum arising from the (π*)2 configuration of the chalcogen dimers, namely the X21, a2 and b0+ states, is calculated using Wave-Function Theory (WFT) based methods. Two-component (2c) and four-component (4c) MultiReference Configuration Interaction (MRCI) and Fock-Space Coupled Cluster (FSCC......) methods are used as well as two-step methods Spin-Orbit Complete Active Space Perturbation Theory at 2nd order (SO-CASPT2) and Spin-Orbit Difference Dedicated Configuration Interaction (SODDCI). The energy of the X21 state corresponds to the Zero-Field Splitting (ZFS) of the ground state spin triplet...
Resonance state wave functions of 15Be using supersymmetric quantum mechanics
Dutta, S. K.; Gupta, D.; Saha, Swapan K.
2018-01-01
The theoretical procedure of supersymmetric quantum mechanics is adopted to generate the resonance state wave functions of the unbound nucleus 15Be. In this framework, we used a density dependent M3Y microscopic potential and arrived at the energy and width of the 1.8 MeV (5/2+) resonance state. We did not find any other nearby resonances for 15Be. It becomes apparent that the present framework is a powerful tool to theoretically complement the increasingly important accelerator based experiments with unbound nuclei.
Tapsanit, Piyawath; Yamashita, Masatsugu; Otani, Chiko
2014-01-13
The analytical solutions of the electromagnetic waves in the inhomogeneous cylindrical hyperlens (CH) comprising concentric cylindrical layers (CCLs) with multiple point sources located either outside the structure in the focusing process or inside the core in the magnifying process are obtained by means of Green's function analysis. The solutions are consistent with FDTD simulation in both processes. The sub-wavelength focal spot λ/16.26 from two point sources with wavelength 465 nm is demonstrated in the CH made by alternating silver and silica CCLs. Our solutions are expected to be the efficient tools for designing the sub-wavelength focusing and imaging cylindrical hyperlens.
Topological Invariants and Ground-State Wave functions of Topological Insulators on a Torus
Directory of Open Access Journals (Sweden)
Zhong Wang
2014-01-01
Full Text Available We define topological invariants in terms of the ground-state wave functions on a torus. This approach leads to precisely defined formulas for the Hall conductance in four dimensions and the topological magnetoelectric θ term in three dimensions, and their generalizations in higher dimensions. They are valid in the presence of arbitrary many-body interactions and disorder. These topological invariants systematically generalize the two-dimensional Niu-Thouless-Wu formula and will be useful in numerical calculations of disordered topological insulators and strongly correlated topological insulators, especially fractional topological insulators.
Genoni, Marco G.; Duarte, O. S.; Serafini, Alessio
2016-10-01
Inspired by the notion that environmental noise is in principle observable, while fundamental noise due to spontaneous localization would not be, we study the estimation of the diffusion parameter induced by wave function collapse models under continuous monitoring of the environment. We take into account finite measurement efficiencies and, in order to quantify the advantage granted by monitoring, we analyse the quantum Fisher information associated with such a diffusion parameter, identify optimal measurements in limiting cases, and assess the performance of such measurements in more realistic conditions.
Imaging dynamical chiral-symmetry breaking: pion wave function on the light front.
Chang, Lei; Cloët, I C; Cobos-Martinez, J J; Roberts, C D; Schmidt, S M; Tandy, P C
2013-03-29
We project onto the light front the pion's Poincaré-covariant Bethe-Salpeter wave function obtained using two different approximations to the kernels of quantum chromodynamics' Dyson-Schwinger equations. At an hadronic scale, both computed results are concave and significantly broader than the asymptotic distribution amplitude, φ(π)(asy)(x)=6x(1-x); e.g., the integral of φ(π)(x)/φ(π)(asy)(x) is 1.8 using the simplest kernel and 1.5 with the more sophisticated kernel. Independent of the kernels, the emergent phenomenon of dynamical chiral-symmetry breaking is responsible for hardening the amplitude.
Das, Ritwick; Kumar, S Chaitanya; Samanta, G K; Ebrahim-Zadeh, M
2009-12-15
We report a compact and viable source of broadband, high-power, cw, mid-IR radiation based on a singly resonant optical parametric oscillator (SRO) pumped by a wide-bandwidth cw Yb fiber laser centered at 1060 nm. By exploiting the extended phase-matching bandwidth in a 50 mm crystal of MgO:PPLN and a ring SRO cavity, we obtain 5.3 W of broadband idler output for 25.5 W of pump at >80% depletion, transferring a pump bandwidth of 73.9 cm(-1) to an idler spectrum spread across an equal bandwidth centered at 3454 nm. By deploying output coupling of the signal, we generate 11.2 W of total power at 44% extraction efficiency with a pump depletion of >73% at the maximum available pump power. Measurements of transverse modal power confirm Gaussian distribution of signal and idler beams.
Harris, Jamie; Timofeeva, Yulia
2010-11-01
Calcium is a crucial component in a plethora of cellular processes involved in cell birth, life, and death. Intercellular calcium waves that can spread through multiple cells provide one form of cellular communication mechanism between various parts of cell tissues. Here we introduce a simple, yet biophysically realistic model for the propagation of intercellular calcium waves based on the fire-diffuse-fire type model for calcium dynamics. Calcium release sites are considered to be discretely distributed along individual linear cells that are connected by gap junctions and a solution of this model can be found in terms of the Green's function for this system. We develop the "sum-over-trips" formalism that takes into account the boundary conditions at gap junctions providing a generalization of the original sum-over-trips approach for constructing the response function for branched neural dendrites. We obtain the exact solution of the Green's function in the Laplace (frequency) domain for an infinite array of cells and show that this Green's function can be well approximated by its truncated version. This allows us to obtain an analytical traveling wave solution for an intercellular calcium wave and analyze the speed of solitary wave propagation as a function of physiologically important system parameters. Periodic and irregular traveling waves can be also sustained by the proposed model.
Energy Technology Data Exchange (ETDEWEB)
Fattebert, J
2008-07-29
We describe an iterative algorithm to solve electronic structure problems in Density Functional Theory. The approach is presented as a Subspace Accelerated Inexact Newton (SAIN) solver for the non-linear Kohn-Sham equations. It is related to a class of iterative algorithms known as RMM-DIIS in the electronic structure community. The method is illustrated with examples of real applications using a finite difference discretization and multigrid preconditioning.
Lee, Ji-Hyun; Lee, Sangyong; Choi, SeokJoo; Choi, Yoon-Hee; Lee, Kwansub
2017-01-01
[Purpose] The purpose of this study was to identify the effects of extracorporeal shock wave therapy on the pain and function of patients with degenerative knee arthritis. [Subjects and Methods] Twenty patients with degenerative knee arthritis were divided into a conservative physical therapy group (n=10) and an extracorporeal shock wave therapy group (n=10). Both groups received general conservative physical therapy, and the extracorporeal shock wave therapy was additionally treated with extracorporeal shock wave therapy after receiving conservative physical therapy. Both groups were treated three times a week over a four-week period. The visual analogue scale was used to evaluate pain in the knee joints of the subjects, and the Korean Western Ontario and McMaster Universities Osteoarthritis Index was used to evaluate the function of the subjects. [Results] The comparison of the visual analogue scale and Korean Western Ontario and McMaster Universities Osteoarthritis Index scores within each group before and after the treatment showed statistically significant declines in scores in both the conservative physical therapy group and extracorporeal shock wave therapy group. A group comparison after the treatment showed statistically significant differences in these scores in the extracorporeal shock wave therapy group and the conservative physical therapy group. [Conclusion] extracorporeal shock wave therapy may be a useful nonsurgical intervention for reducing the pain of patients with degenerative knee arthritis and improving these patients’ function. PMID:28356649
Vergho, Daniel; Burger, Maximilian; Schrammel, Moritz; Brookman-May, Sabine; Gierth, Michael; Hoschke, Bernd; Lopau, Kai; Gilfrich, Christian; Riedmiller, Hubertus; Wolff, Ingmar; May, Matthias
2015-05-01
Living kidney donation (LKD) involves little risk for the donor and provides excellent functional outcome for transplant recipients. However, contradictory data exist on the incidence and degree of impaired renal function (IRF) in the donor. Only few studies compared the incidence of IRF in donors with that of patients having undergone radical nephrectomy (RN). From 1992 to 2012, 94 healthy subjects underwent an open nephrectomy for living kidney donation at the University Medical Center of Würzburg. These patients were compared with matched subjects who had the same surgical procedure for renal cell carcinoma at the Carl-Thiem Hospital Cottbus (1:1 matching using propensity scores). In the LKD-group, no complication ≥ Grade 3 according to the Clavien-Dindo classification occurred. Donors had a preoperative median estimated glomerular filtration rate (eGFR) of 85.1 ml/min which changed to 54.4, 57.0 and 61.0 ml/min (all p kidney donors, median eGFR decreased by 34.4 % immediately after surgery. Compared with matched RN-patients, immediate postoperative IRF is significantly more pronounced. One explanation may be that in kidney tumor patients, compensatory adaptive filtration activity of the contralateral kidney sets in already preoperatively.
Shul'ga, N. F.; Syshchenko, V. V.; Tarnovsky, A. I.; Solovyev, I. I.; Isupov, A. Yu.
2018-01-01
The motion of fast electrons through the crystal during axial channeling could be regular and chaotic. The dynamical chaos in quantum systems manifests itself in both statistical properties of energy spectra and morphology of wave functions of the individual stationary states. In this report, we investigate the axial channeling of high and low energy electrons and positrons near [100] direction of a silicon crystal. This case is particularly interesting because of the fact that the chaotic motion domain occupies only a small part of the phase space for the channeling electrons whereas the motion of the channeling positrons is substantially chaotic for the almost all initial conditions. The energy levels of transverse motion, as well as the wave functions of the stationary states, have been computed numerically. The group theory methods had been used for classification of the computed eigenfunctions and identification of the non-degenerate and doubly degenerate energy levels. The channeling radiation spectrum for the low energy electrons has been also computed.
Niels Bohr on the wave function and the classical/quantum divide
Zinkernagel, Henrik
2016-02-01
It is well known that Niels Bohr insisted on the necessity of classical concepts in the account of quantum phenomena. But there is little consensus concerning his reasons, and what he exactly meant by this. In this paper, I re-examine Bohr's interpretation of quantum mechanics, and argue that the necessity of the classical can be seen as part of his response to the measurement problem. More generally, I attempt to clarify Bohr's view on the classical/quantum divide, arguing that the relation between the two theories is that of mutual dependence. An important element in this clarification consists in distinguishing Bohr's idea of the wave function as symbolic from both a purely epistemic and an ontological interpretation. Together with new evidence concerning Bohr's conception of the wave function collapse, this sets his interpretation apart from both standard versions of the Copenhagen interpretation, and from some of the reconstructions of his view found in the literature. I conclude with a few remarks on how Bohr's ideas make much sense also when modern developments in quantum gravity and early universe cosmology are taken into account.
Modification of AMD wave functions and application to the breaking of the N=20 magic number
Energy Technology Data Exchange (ETDEWEB)
Kimura, Masaaki; Horiuchi, Hisashi [Kyoto Univ. (Japan). Dept. of Physics
2001-09-01
By using the deformed Gaussian instead of the spherical one, we have modified the AMD (Antisymmetrized Molecular Dynamics) wave functions. The calculation results with this modified AMD shows the drastic improvement of the deformation properties of Mg isotopes. This improvement means that this new version of AMD can treat the deformation of mean field properly than before and the deformation of mean field is important in Mg isotopes. With this new version of AMD, we have also calculated 32Mg in which the breaking of magic number N=20 is experimentally known. In this nucleus, {beta}-energy surface is also drastically changed by the modification AMD wave function. Our results show that this nucleus is indeed deformed and neutron's 2p2h state is dominant in its ground state. This ground state reproduces the experimental data and shows the breaking of the magic number N=20 clearly. Additionally, near the ground state, there is also very interesting state which has neutron's 4p4h structure and shows parity violating density distribution and cluster-like nature. (author)
Microscopy of electronic wave function; Microscopie de fonction d'onde electronique
Energy Technology Data Exchange (ETDEWEB)
Harb, M.
2010-09-15
This work of thesis aims to visualize, on a position sensitive detector, the spatial oscillations of slow electrons ({approx} meV) emitted by a threshold photoionization in the presence of an external electric field. The interference figure obtained represents the square magnitude of electronic wavefunction. This fundamental work allows us to have access to the electronic dynamics and thus to highlight several quantum mechanisms that occur at the atomic scale (field Coulomb, electron/electron interaction..). Despite the presence an electronic core in Li atom, we have succeeded, experimentally and for the first time, in visualizing the wave function associated with the quasi-discrete Stark states coupled to the ionization continuum. Besides, using simulations of wave packet propagation, based on the 'Split-operator' method, we have conducted a comprehensive study of the H, Li and Cs atoms while revealing the significant effects of the Stark resonances. A very good agreement, on and off resonances, was obtained between simulated and experimental results. In addition, we have developed a generalized analytical model to understand deeply the function of VMI (Velocity-Map Imaging) spectrometer. This model is based on the paraxial approximation; it is based on matrix optics calculation by making an analogy between the electronic trajectory and the light beam. An excellent agreement was obtained between the model predictions and the experimental results. (author)
Gutzwiller wave function for finite systems: superconductivity in the Hubbard model.
Tomski, Andrzej; Kaczmarczyk, Jan
2016-05-05
We study the superconducting phase of the Hubbard model using the Gutzwiller variational wave function (GWF) and the recently proposed diagrammatic expansion technique (DE-GWF). The DE-GWF method works on the level of the full GWF and in the thermodynamic limit. Here, we consider a finite-size system to study the accuracy of the results as a function of the system size (which is practically unrestricted). We show that the finite-size scaling used, e.g. in the variational Monte Carlo method can lead to significant, uncontrolled errors. The presented research is the first step towards applying the DE-GWF method in studies of inhomogeneous situations, including systems with impurities, defects, inhomogeneous phases, or disorder.
Retrieval of Green's functions of elastic waves from thermal fluctuations of fluid-solid systems.
Godin, Oleg A
2009-04-01
Fluctuation-dissipation and flow reversal theorems are used to study long-range correlation of thermal phonons in a stationary heterogeneous mechanical system comprised of arbitrary inhomogeneous fluid flow and anisotropic solid. At thermal equilibrium, with an appropriate choice of physical observables to characterize thermal fluctuations within the fluid and within the solid, the general integral expression for the two-point correlation function of the fluctuations reduces to a linear combination of deterministic Green's functions, which describe wave propagation in opposite directions between the two points. It is demonstrated that the cross-correlation of thermal noise contains as much information about the environment as can be obtained in active reciprocal transmission experiments with transceivers placed at the two points. These findings suggest a possible application of ambient noise cross-correlation to passive acoustic characterization of inhomogeneous flows in fluid-solid systems in laboratory and geophysical settings.
Salati, Michele; Brunelli, Alessandro; Xiumè, Francesco; Monteverde, Marco; Sabbatini, Armando; Tiberi, Michela; Pompili, Cecilia; Palloni, Roberto; Refai, Majed
2017-06-01
The objective of the present study was to compare functional loss [forced expiratory volume in one second to forced vital capacity ratio (FEV1), DLCO and VO2max reduction] after VATS versus open lobectomies. We performed a prospective observational study on 195 patients who had a pulmonary lobectomy from June 2010 to November 2014 and who were able to complete a 3-months functional evaluation follow-up program. Since the VATS technique was our first choice for performing lobectomies from January 2012, we divided the patients into two groups: the OPEN group (112 patients) and the VATS group (83 patients). The open approach was intended as a muscle sparing/nerve sparing lateral thoracotomy. Fourteen baseline factors were used to construct a propensity score to match the VATS-group patients with their OPEN-group counterparts. These two matched groups were then compared in terms of reduction of FEV1, DLCO and VO2max (Mann-Whitney test). The propensity score analysis yielded 83 well-matched pairs of OPEN and VATS patients. In both groups, 3 months postoperatively, we found a reduction in FEV1, DLCO and VO2max values (OPEN patients: FEV1-10%, DLCO -11.9%, VO2max - 5.5%; VATS patients: FEV1-7.2%, DLCO-10.6%, VO2max-6.9%). The reductions in FEV1, DLCO and VO2max were similar to those in the two matched groups, with a Cohen effect size advantages in terms of FEV1, DLCO and exercise capacity recovery in comparison to the muscle-sparing thoracotomy approach.
Palomeras, I.; Thurner, S.; Levander, A.; Humphreys, E.; Miller, M. S.; Carbonell, R.; Gallart, J.
2012-04-01
The western Mediterranean is a diffuse plate boundary separating the African and Eurasian plates. Cenozoic deformation is centered on the Gibraltar arc and Alboran Sea, and occupies a wide area from the southern Iberian Massif in Spain to the Atlas Mountains in Morocco. We present a model of the lithospheric structure of this region derived from Rayleigh wave tomography and Ps receiver functions, using data from the PICASSO (Program to Investigate Convective Alboran Sea System Overturn) linear broadband array of ~100 seismographs. This array is deployed from central Spain to the Morocco-Algerian border. We complement these data with some of that recorded by IberArray, an areal broadband array, operated by the Spanish seismological community, covering the same region with a uniform 50 km x 50 km grid of stations. Rayleigh phase velocities have been measured from 20-167s period using the two-plane-wave method to remove complications due to multi-pathing, and finite-frequency kernels to improve lateral resolution. The phase velocities were inverted for 1D structure on a 0.25 by 0.25 degree grid. Ps receiver functions at 1Hz and 2Hz were calculated for the same area using water-level and time-domain iterative deconvolution, and were then CCP stacked. The Rayleigh wave shear velocity model, jointly interpreted with the discontinuity structure from the CCP stack, shows the first-order lithospheric structure, and the lithosphere-asthenosphere boundary (LAB). From north to south along the PICASSO profile: The lithosphere is ~120 km thick beneath the Iberian Massif, where it has the highest shear velocity, 4.45 km/s. To the south the lithosphere thins dramatically beneath the Betic Mountains to ~85 km, and then varies in thickness and decreases in velocity beneath the Alboran Sea and Gibraltar Arc. The thinnest lithosphere, ~60 km, is observed beneath the Rif mountains and Middle Atlas, with a low velocity feature (4.2 km/s) at ~60 km depth beneath a site of Late Cenozoic
Directory of Open Access Journals (Sweden)
Simeng Zhu
2014-12-01
Full Text Available Athletic training can result in increased left ventricular (LV wall thickness, termed physiologic hypertrophy (PhH. By contrast, pathologic hypertrophy (PaH can be due to hypertension, aortic stenosis, or genetic mutation causing hypertrophic cardiomyopathy (HCM. Because morphologic (LV dimension, wall thickness, mass, etc. and functional index similarities (LV ejection fraction, cardiac output, peak filling rate, etc. limit diagnostic specificity, ability to differentiate between PhH and PaH is important. Conventional echocardiographic diastolic function (DF indexes have limited ability to differentiate between PhH and PaH and cannot provide information on chamber property (stiffness and relaxation. We hypothesized that kinematic model-based DF assessment can differentiate between PhH and PaH and, by providing chamber properties, has even greater value compared with conventional metrics. For validation, we assessed DF in the following three age-matched groups: pathologic (HCM hypertrophy (PaH, n = 14, PhH (Olympic rowers, PhH, n = 21, and controls (n = 21. Magnetic resonance imaging confirmed presence of both types of hypertrophy and determined LV mass and chamber size. Model-based indexes, chamber stiffness (k, relaxation/viscoelasticity (c, and load (xo and conventional indexes, Epeak (peak of E-wave, ratio of Epeak to Apeak (E/A, E-wave acceleration time (AT, and E-wave deceleration time (DT were computed. We analyzed 1588 E waves distributed as follows: 328 (PaH, 672 (athletes, and 588 (controls. Among conventional indexes, Epeak and E-wave DT were similar between PaH and PhH, whereas E/A and E-wave AT were lower in PaH. Model-based analysis showed that PaH had significantly higher relaxation/viscoelasticity (c and chamber stiffness (k than PhH. The physiologic equation of motion for filling-based derivation of the model provides a mechanistic understanding of the differences between PhH and PaH.
Matsue, Yuya; Shiraishi, Atsushi; Kagiyama, Nobuyuki; Yoshida, Kazuki; Kume, Teruyoshi; Okura, Hiroyuki; Suzuki, Makoto; Matsumura, Akihiko; Yoshida, Kiyoshi; Hashimoto, Yuji
2016-12-01
Although intravenous diuretics have been mainstay drugs in patients with acute heart failure (AHF), they have been suggested to have some deleterious effects on prognosis. We postulated that renal function may modify their deleterious effects in AHF patients. The study population consisted of 1094 AHF patients from three hospitals. Renal dysfunction (RD) was defined as estimated glomerular filtration rate (eGFR) renal function in AHF. This association may be one reason for poorer prognosis of AHF patients complicated with renal impairment.
Schuld, J; Richter, S; Eisele, R M; Von Heesen, M; Roller, J; Glanemann, M
2015-06-01
The aim of this paper was to compare healthy subjects and patients after total mesorectal excision concerning anal resting/squeeze pressure and surface-electromyography of the sphincter. Forty patients (9 female/31 male) after total mesorectal excision due to low or middle rectal cancer were compared to a sex-, age- and BMI-matched group of healthy volunteers by means of anorectal pull-through manometry using a microtip-transducer system and by means of endoanal surface electromyography using a bipolar plug electrode. Resting pressure (59.2 ± 3.1 mmHg vs. 68.3 ± 4.3 mmHg; P=0.056) and squeeze pressure (127.3 ± 3.2 mmHg vs. 128.9 ± 4.6 mmHg; P=0.78) were comparable between patients after total mesorectal excision and healthy volunteers whereas surface electromyography amplitude (9.5 ± 0.4 µV vs. 13.9 ± 0.6 µV; P=0.01) was significant lower in patients after total mesorectal excision compared to healthy subjects. Correlation between squeeze and resting pressure as well as between squeeze pressure and surface electromyography were weaker in patients after total mesorectal excision compared to healthy controls. Objective measurable sphincter pressure after total mesorectal excision seems to be comparable to that of healthy subjects whereas surface-electromyography is significant higher in healthy subjects.
Eshghi, M.; Mehraban, H.; Azar, I. Ahmadi
2017-10-01
In this research, firstly, by using the new form of Dirac-Weyl equation and the series method with submitting more suitable details, the energy spectrum and wave functions of the massless Dirac fermions are calculated under the inhomogeneous and q-deformed spatially magnetic fields. Although, we discussed about the results of the energy levels, further, we obtained the wave function as the Hessenberg determinant with calculating the elements of it as exact. On the other hand, by using the Mellin-Barnes integral representation and Hurwitz zeta function, we have achieved the thermodynamic physical quantities of the Dirac-Weyl fermions in the absence of a magnetic field for inside of the graphene quantum dot. Finally, our numerical results for the wave functions and probability densities are presented too.
Energy Technology Data Exchange (ETDEWEB)
Khan, Shehryar, E-mail: sherkhan@fysik.su.se; Odelius, Michael, E-mail: odelius@fysik.su.se [Department of Physics, Stockholm University, AlbaNova University Center, S-106 91 Stockholm (Sweden); Kubica-Misztal, Aleksandra [Institute of Physics, Jagiellonian University, ul. Reymonta 4, PL-30-059 Krakow (Poland); Kruk, Danuta [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Sloneczna 54, Olsztyn PL-10710 (Poland); Kowalewski, Jozef [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm (Sweden)
2015-01-21
The zero-field splitting (ZFS) of the electronic ground state in paramagnetic ions is a sensitive probe of the variations in the electronic and molecular structure with an impact on fields ranging from fundamental physical chemistry to medical applications. A detailed analysis of the ZFS in a series of symmetric Gd(III) complexes is presented in order to establish the applicability and accuracy of computational methods using multiconfigurational complete-active-space self-consistent field wave functions and of density functional theory calculations. The various computational schemes are then applied to larger complexes Gd(III)DOTA(H{sub 2}O){sup −}, Gd(III)DTPA(H{sub 2}O){sup 2−}, and Gd(III)(H{sub 2}O){sub 8}{sup 3+} in order to analyze how the theoretical results compare to experimentally derived parameters. In contrast to approximations based on density functional theory, the multiconfigurational methods produce results for the ZFS of Gd(III) complexes on the correct order of magnitude.
Energy Technology Data Exchange (ETDEWEB)
Fauqueux, S.
2003-02-01
We consider the propagation of elastic waves in unbounded domains. A new formulation of the linear elasticity system as an H (div) - L{sup 2} system enables us to use the 'mixed spectral finite element method', This new method is based on the definition of new spaces of approximation and the use of mass-lumping. It leads to an explicit scheme with reduced storage and provides the same solution as the spectral finite element method. Then, we model unbounded domains by using Perfectly Matched Layers. Instabilities in the PML in the case of particular 2D elastic media are pointed out and investigated. The numerical method is validated and tested in the case of acoustic and elastic realistic models. A plane wave analysis gives results about numerical dispersion and shows that meshes adapted to the physical and geometrical properties of the media are more accurate than the others. Then, an extension of the method to fluid-solid coupling is introduced for 2D seismic propagation. (author)
Two-state model based on the block-localized wave function method
Mo, Yirong
2007-06-01
The block-localized wave function (BLW) method is a variant of ab initio valence bond method but retains the efficiency of molecular orbital methods. It can derive the wave function for a diabatic (resonance) state self-consistently and is available at the Hartree-Fock (HF) and density functional theory (DFT) levels. In this work we present a two-state model based on the BLW method. Although numerous empirical and semiempirical two-state models, such as the Marcus-Hush two-state model, have been proposed to describe a chemical reaction process, the advantage of this BLW-based two-state model is that no empirical parameter is required. Important quantities such as the electronic coupling energy, structural weights of two diabatic states, and excitation energy can be uniquely derived from the energies of two diabatic states and the adiabatic state at the same HF or DFT level. Two simple examples of formamide and thioformamide in the gas phase and aqueous solution were presented and discussed. The solvation of formamide and thioformamide was studied with the combined ab initio quantum mechanical and molecular mechanical Monte Carlo simulations, together with the BLW-DFT calculations and analyses. Due to the favorable solute-solvent electrostatic interaction, the contribution of the ionic resonance structure to the ground state of formamide and thioformamide significantly increases, and for thioformamide the ionic form is even more stable than the covalent form. Thus, thioformamide in aqueous solution is essentially ionic rather than covalent. Although our two-state model in general underestimates the electronic excitation energies, it can predict relative solvatochromic shifts well. For instance, the intense π →π* transition for formamide upon solvation undergoes a redshift of 0.3eV, compared with the experimental data (0.40-0.5eV).
Kemp, B J; Adams, B M; Campbell, M L
1997-02-01
To compare depressive symptoms and life satisfaction in aging polio survivors with age-matched controls and to relate these outcomes to scores to psychosocial and disability-related variables. A planned medical, functional, and psychosocial study with multivariate analyses. A large, urban rehabilitation center. A volunteer sample of 121 polio survivors and an age-matched control group of 60 people with similar sociodemographic backgrounds. Depression as measured by the Geriatric Depression Scale and an 11-item life satisfaction scale. The prevalence of depressive disorders was not significantly different in the two groups, although the postpolio group tended to have more symptomatology and an overall depressive disorder prevalence of 28%. Some life satisfaction scale scores were significantly lower in the postpolio group, especially those concerned with health. People with postpolio syndrome scored significantly higher on depression scales and lower on some life satisfaction scales than people with a history of polio but without postpolio syndrome. Several psychosocial variables, most notably family functioning and attitude toward disability, helped to mediate this effect. Among people with significant depression, there was little, evidence of adequate treatment in the community. Postpolio by itself does not relate to higher depression scores or lower life satisfaction. Postpolio syndrome has some relation to depression, but family functioning and attitude toward disability are more important. There is a need for better community-based psychological services.
Orbital-free density functional theory implementation with the projector augmented-wave method
Energy Technology Data Exchange (ETDEWEB)
Lehtomäki, Jouko; Makkonen, Ilja; Harju, Ari; Lopez-Acevedo, Olga, E-mail: olga.lopez.acevedo@aalto.fi [COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto (Finland); Caro, Miguel A. [COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto (Finland); Department of Electrical Engineering and Automation, Aalto University, Espoo (Finland)
2014-12-21
We present a computational scheme for orbital-free density functional theory (OFDFT) that simultaneously provides access to all-electron values and preserves the OFDFT linear scaling as a function of the system size. Using the projector augmented-wave method (PAW) in combination with real-space methods, we overcome some obstacles faced by other available implementation schemes. Specifically, the advantages of using the PAW method are twofold. First, PAW reproduces all-electron values offering freedom in adjusting the convergence parameters and the atomic setups allow tuning the numerical accuracy per element. Second, PAW can provide a solution to some of the convergence problems exhibited in other OFDFT implementations based on Kohn-Sham (KS) codes. Using PAW and real-space methods, our orbital-free results agree with the reference all-electron values with a mean absolute error of 10 meV and the number of iterations required by the self-consistent cycle is comparable to the KS method. The comparison of all-electron and pseudopotential bulk modulus and lattice constant reveal an enormous difference, demonstrating that in order to assess the performance of OFDFT functionals it is necessary to use implementations that obtain all-electron values. The proposed combination of methods is the most promising route currently available. We finally show that a parametrized kinetic energy functional can give lattice constants and bulk moduli comparable in accuracy to those obtained by the KS PBE method, exemplified with the case of diamond.
Expansion of arbitrary electromagnetic fields in terms of vector spherical wave functions.
Moreira, Wendel Lopes; Neves, Antonio Alvaro Ranha; Garbos, Martin K; Euser, Tijmen G; Cesar, Carlos Lenz
2016-02-08
Since 1908, when Mie reported analytical expressions for the fields scattered by a spherical particle upon incidence of plane-waves, generalizing his analysis for the case of an arbitrary incident wave has been an open question because of the cancellation of the prefactor radial spherical Bessel function. This cancellation was obtained before by our own group for a highly focused beam centered in the objective. In this work, however, we show for the first time how these terms can be canceled out for any arbitrary incident field that satisfies Maxwells equations, and obtain analytical expressions for the beam shape coefficients. We show several examples on how to use our method to obtain analytical beam shape coefficients for: Bessel beams, general hollow waveguide modes and specific geometries such as cylindrical and rectangular. Our method uses the vector potential, which shows the interesting characteristic of being gauge invariant. These results are highly relevant for speeding up numerical calculation of light scattering applications such as the radiation forces acting on spherical particles placed in an arbitrary electromagnetic field, as in an optical tweezers system.
Grand canonical ensemble, multi-particle wave functions and scattering data
Bruckmann, Falk; Kloiber, Thomas; Sulejmanpasic, Tin
2015-01-01
We show that information about scattering data of a quantum field theory can be obtained from studying the system at finite density and low temperatures. In particular we consider models formulated on the lattice which can be exactly dualized to theories of conserved charge fluxes on lattice links. Apart from eliminating the complex action problem at nonzero chemical potential mu, these dualizations allow for a particle world line interpretation of the dual fluxes from which one can extract data about the 2-particle wave function. As an example we perform dual Monte Carlo simulations of the 2-dimensional O(3) model at nonzero mu and finite volume, whose non-perturbative spectrum consists of a massive triplet of particles. At nonzero mu particles are induced in the system, which at sufficiently low temperature give rise to sectors of fixed particle number. We show that the scattering phase shifts can be obtained either from the critical chemical potential values separating the sectors or directly from the wave...
Conformal field theory construction for non-Abelian hierarchy wave functions
Tournois, Yoran; Hermanns, Maria
2017-12-01
The fractional quantum Hall effect is the paradigmatic example of topologically ordered phases. One of its most fascinating aspects is the large variety of different topological orders that may be realized, in particular non-Abelian ones. Here we analyze a class of non-Abelian fractional quantum Hall model states which are generalizations of the Abelian Haldane-Halperin hierarchy. We derive their topological properties and show that the quasiparticles obey non-Abelian fusion rules of type su (q)k . For a subset of these states we are able to derive the conformal field theory description that makes the topological properties—in particular braiding—of the state manifest. The model states we study provide explicit wave functions for a large variety of interesting topological orders, which may be relevant for certain fractional quantum Hall states observed in the first excited Landau level.
Peng, H L; Schober, H R; Voigtmann, Th
2016-12-01
Molecular dynamic simulations are performed to reveal the long-time behavior of the velocity autocorrelation function (VAF) by utilizing the finite-size effect in a Lennard-Jones binary mixture. Whereas in normal liquids the classical positive t^{-3/2} long-time tail is observed, we find in supercooled liquids a negative tail. It is strongly influenced by the transfer of the transverse current wave across the period boundary. The t^{-5/2} decay of the negative long-time tail is confirmed in the spectrum of VAF. Modeling the long-time transverse current within a generalized Maxwell model, we reproduce the negative long-time tail of the VAF, but with a slower algebraic t^{-2} decay.
Directory of Open Access Journals (Sweden)
Y. Kamiya
2014-01-01
Full Text Available Gravity is the most familiar force at our natural length scale. However, it is still exotic from the view point of particle physics. The first experimental study of quantum effects under gravity was performed using a cold neutron beam in 1975. Following this, an investigation of gravitationally bound quantum states using ultracold neutrons was started in 2002. This quantum bound system is now well understood, and one can use it as a tunable tool to probe gravity. In this paper, we review a recent measurement of position-space wave functions of such gravitationally bound states and discuss issues related to this analysis, such as neutron loss models in a thin neutron guide, the formulation of phase space quantum mechanics, and UCN position sensitive detectors. The quantum modulation of neutron bound states measured in this experiment shows good agreement with the prediction from quantum mechanics.
A TOCA/CDC-42/PAR/WAVE functional module required for retrograde endocytic recycling.
Bai, Zhiyong; Grant, Barth D
2015-03-24
Endosome-to-Golgi transport is required for the function of many key membrane proteins and lipids, including signaling receptors, small-molecule transporters, and adhesion proteins. The retromer complex is well-known for its role in cargo sorting and vesicle budding from early endosomes, in most cases leading to cargo fusion with the trans-Golgi network (TGN). Transport from recycling endosomes to the TGN has also been reported, but much less is understood about the molecules that mediate this transport step. Here we provide evidence that the F-BAR domain proteins TOCA-1 and TOCA-2 (Transducer of Cdc42 dependent actin assembly), the small GTPase CDC-42 (Cell division control protein 42), associated polarity proteins PAR-6 (Partitioning defective 6) and PKC-3/atypical protein kinase C, and the WAVE actin nucleation complex mediate the transport of MIG-14/Wls and TGN-38/TGN38 cargo proteins from the recycling endosome to the TGN in Caenorhabditis elegans. Our results indicate that CDC-42, the TOCA proteins, and the WAVE component WVE-1 are enriched on RME-1-positive recycling endosomes in the intestine, unlike retromer components that act on early endosomes. Furthermore, we find that retrograde cargo TGN-38 is trapped in early endosomes after depletion of SNX-3 (a retromer component) but is mainly trapped in recycling endosomes after depletion of CDC-42, indicating that the CDC-42-associated complex functions after retromer in a distinct organelle. Thus, we identify a group of interacting proteins that mediate retrograde recycling, and link these proteins to a poorly understood trafficking step, recycling endosome-to-Golgi transport. We also provide evidence for the physiological importance of this pathway in WNT signaling.
A TOCA/CDC-42/PAR/WAVE functional module required for retrograde endocytic recycling
Bai, Zhiyong; Grant, Barth D.
2015-01-01
Endosome-to-Golgi transport is required for the function of many key membrane proteins and lipids, including signaling receptors, small-molecule transporters, and adhesion proteins. The retromer complex is well-known for its role in cargo sorting and vesicle budding from early endosomes, in most cases leading to cargo fusion with the trans-Golgi network (TGN). Transport from recycling endosomes to the TGN has also been reported, but much less is understood about the molecules that mediate this transport step. Here we provide evidence that the F-BAR domain proteins TOCA-1 and TOCA-2 (Transducer of Cdc42 dependent actin assembly), the small GTPase CDC-42 (Cell division control protein 42), associated polarity proteins PAR-6 (Partitioning defective 6) and PKC-3/atypical protein kinase C, and the WAVE actin nucleation complex mediate the transport of MIG-14/Wls and TGN-38/TGN38 cargo proteins from the recycling endosome to the TGN in Caenorhabditis elegans. Our results indicate that CDC-42, the TOCA proteins, and the WAVE component WVE-1 are enriched on RME-1–positive recycling endosomes in the intestine, unlike retromer components that act on early endosomes. Furthermore, we find that retrograde cargo TGN-38 is trapped in early endosomes after depletion of SNX-3 (a retromer component) but is mainly trapped in recycling endosomes after depletion of CDC-42, indicating that the CDC-42–associated complex functions after retromer in a distinct organelle. Thus, we identify a group of interacting proteins that mediate retrograde recycling, and link these proteins to a poorly understood trafficking step, recycling endosome-to-Golgi transport. We also provide evidence for the physiological importance of this pathway in WNT signaling. PMID:25775511
TUNING IN TO FISH SWIMMING WAVES - BODY FORM, SWIMMING MODE AND MUSCLE FUNCTION
WARDLE, CS; VIDELER, JJ; ALTRINGHAM, JD
Most fish species swim with lateral body undulations running from head to tail, These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water, The coupling between both waves
Wave function of the Universe, preferred reference frame effects and metric signature transition
Ghaffarnejad, Hossein
2013-01-01
Extending the Brans Dicke (BD) gravity theory in the presence of power-law self interacting potential $\\thicksim\\phi^n,$ action functional of a dynamical unit-time-like four vector field $N_{\\mu}$ and action functional of perfect fluid matter field, we study classical and quantum approaches of a flat Robertson-Walker (RW) space time. In the classical approach we use slow-roll condition of the potential $V(\\phi),$ and obtain power-law inflationary cosmological model which exhibits metric signature transition at the origin of time. Our solution follows $n\\approx-4,$ with negative barotropic index $\\gamma\\approx-1$ corresponding to dark matter perfect fluid and $\\omega\\geq4\\times10^4$ corresponding to the experimentally redicted value on the BD parameter. Deceleration parameter is obtained also as $q\\approx-1.$ Applying a minisuperspace model of quantum cosmology, we derive corresponding Wheeler DeWitt (WD) wave functional equation of the system with a nonzero ADM mass. Minisuperspace potential of the WD equatio...
Projector Augmented Wave formulation of orbital-dependent exchange-correlation functionals
Xu, Xiao; Holzwarth, N. A. W.
2012-02-01
The use of orbital-dependent exchange-correlation functionals within electronic structure calculations has recently received renewed attention for improving the accuracy of the calculations, especially correcting self-interaction errors. Since the Projector Augmented Wave (PAW) methodootnotetext P. Bl"ochl, Phys. Rev. B 50, 17953 (1994). is an efficient pseudopotential-like scheme which ensures accurate evaluation of all multipole moments of direct and exchange Coulomb integrals, it is a natural choice for implementing orbital-dependent formalisms. Using Fock exchange as an example of an orbital-dependent functional, we developed the formulation and numerical implementation of the approximate optimized effective potential formalism of Kreiger, Li, and Iafrate (KLI)ootnotetext J. B. Krieger, Y. Li, and G. J. Iafrate Phys. Rev. A 45, 101 (1992). within the PAW method, comparing results with the analogous Hartree-Fock treatment.ootnotetext Xiao Xu and N. A. W. Holzwarth, Phys. Rev. B 81, 245105 (2010); 84, 155113 (2011). Test results are presented for ground state properties of two well-known materials -- diamond and LiF. This formalism can be extended to treat orbital-dependent functionals more generally.
Qian, Zheng-Hua; Jin, Feng; Lu, Tianjian; Kishimoto, Kikuo; Hirose, Sohichi
2010-01-01
The effect of initial stress on the propagation behavior of Love waves in a piezoelectric half-space of polarized ceramics carrying a functionally graded material (FGM) layer is analytically investigated in this paper from the three-dimensional equations of linear piezoelectricity. The analytical solutions are obtained for the dispersion relations of Love wave propagating in this kind of structure with initial stress for both electrical open case and electrical short case, respectively. One numerical example is given to graphically illustrate the effect of initial stress on dispersive curve, phase velocity and electromechanical coupling factor of the Love wave propagation. The results reported here are meaningful for the design of surface acoustic wave (SAW) devices with high performance.
Flatté, Stanley M.; Stoughton, Roland B.
1986-06-01
High-frequency (≳ 1 cpd) variations in travel time of acoustic transmissions over ocean mesoscale distances are known to be dominated by the effects of internal wave displacements of the sound speed stratification (Flatté et al., 1979; Flatté, 1983a). Variations in the difference in travel time between transmissions in opposite directions along the same path (reciprocal transmissions) are dominated by internal wave currents [Munk et al., 1981]. We investigate the usefulness of a two-mooring acoustic system for determining the statistical variances of internal wave displacements and currents as a function of depth, geographical position, and time. We find that Statistical fluctuations in the internal wave field itself prevent recovery of range-dependent information between the two moorings. However, range-averaged information can be obtained about mean energy level and about vertical energy migration. We find that uncertainties in the buoyancy and sound speed profiles do not significantly affect the usefulness of the method.
New function of Mittag-Leffler type and its application in the fractional diffusion-wave equation
Energy Technology Data Exchange (ETDEWEB)
Yu Rui [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)]. E-mail: joyfm810909@yahoo.com.cn; Zhang Hongqing [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)
2006-11-15
The classical Mittag-Leffler (M-L) functions have already proved their efficiency as solutions of fractional-order differential and integral equations. In this paper we introduce a modified M-L type function and deduce its important integral transforms. Then the solution of the initial-boundary value problem for the so-called fractional diffusion-wave equation with real-order time and space derivatives is given by using the inverse Fourier transform of the new function.
Kerangart, Stéphane; Cournoyer, Benoit; Loukiadis, Estelle
2018-02-02
The tropism of pathogenic STEC for foodstuffs and cattle reservoir is related to functional specializations. An investigation of C-source utilization patterns among and between STEC serogroups was performed using omnilog phenotypic microarrays (OM). OM functional groupings were compared with STEC phylogroups, seropathotypes, EFSA's molecular risk assessment groups and serogroups. OM INT reduction activities of 37 STEC strains growing on 190 C-substrates were compared. Each strain had its own specific C-utilization profile but 23% of the substrates was used by all strains, 47% by none, and 30% was variably metabolized. Galactose, mannose, N-acetyl-glucosamine (GlcNAc), and N-acetyl neuraminic acid (Neu5Ac) found in the mucus layer of the bovine small intestine were metabolized by all strains. The 56 most informative substrates divided the C-utilization patterns (CP) into three clusters with: (A) harboring all O157 and O145 strains; (B) all O26 strains, and (C) strains of the other serogroups. Significant correlations between INT reduction values of pair of strains per CP group supported these differentiations. CP of group A and B strains were respectively defective in the use of galactonic acid-γ-lactone and rhamnose. Most CP group C strains grew with l-lyxose. Adjusted Wallace coefficients analyses of the datasets indicated high probabilities for the prediction of the use of glycolic acid, β-hydroxybutyric acid, l-lyxose and d-galactonic acid-γ-lactone and 5-keto-d-gluconic acid by a serogroup. The use of a C-substrate could be predicted from the classification of a strain into a phylogroup or seropathotype. Significantly lower numbers of C-substrates were used by seropathotype A strains like O157 ones. Improvements of STEC identification keys were proposed using the most discriminant C-substrates found in this study. Copyright © 2017 Elsevier B.V. All rights reserved.
Gao, W; Cheng, H; Zhang, S S; Liu, H P
2015-01-01
We have investigated the wave-function feature of Rydberg sodium in a uniform electric field and found that the core-induced interaction of non-hydrogenic atom in electric field can be directly visualized in the wave-function. As is well known, the hydrogen atom in electric field can be separated in parabolic coordinates (\\eta, \\xi), whose eigen-function can show a clear pattern towards negative and positive directions corresponding to the so-called red and blue states without ambiguity, respectively. It can be served as a complete orthogonal basis set to study the core-induced interaction of non-hydrogenic atom in electric field. Owing to complete different patterns of the probability distribution for red and blue states, the interaction can be visualized in the wave-function directly via superposition. Moreover, the constructive and destructive interferences between red and blue states are also observed in the wave-function, explicitly explaining the experimental measurement for the spectral oscillator stre...
Energy Technology Data Exchange (ETDEWEB)
Julia, J; Nyblade, A; Hansen, S; Rodgers, A; Matzel, E
2009-07-06
In this project, we are developing models of lithospheric structure for a wide variety of tectonic regions throughout Eurasia and the Middle East by regionalizing 1D velocity models obtained by jointly inverting P-wave and S-wave receiver functions with Rayleigh wave group and phase velocities. We expect the regionalized velocity models will improve our ability to predict travel-times for local and regional phases, such as Pg, Pn, Sn and Lg, as well as travel-times for body-waves at upper mantle triplication distances in both seismic and aseismic regions of Eurasia and the Middle East. We anticipate the models will help inform and strengthen ongoing and future efforts within the NNSA labs to develop 3D velocity models for Eurasia and the Middle East, and will assist in obtaining model-based predictions where no empirical data are available and for improving locations from sparse networks using kriging. The codes needed to conduct the joint inversion of P-wave receiver functions (PRFs), S-wave receiver functions (SRFs), and dispersion velocities have already been assembled as part of ongoing research on lithospheric structure in Africa. The methodology has been tested with synthetic 'data' and case studies have been investigated with data collected at an open broadband stations in South Africa. PRFs constrain the size and S-P travel-time of seismic discontinuities in the crust and uppermost mantle, SRFs constrain the size and P-S travel-time of the lithosphere-asthenosphere boundary, and dispersion velocities constrain average S-wave velocity within frequency-dependent depth-ranges. Preliminary results show that the combination yields integrated 1D velocity models local to the recording station, where the discontinuities constrained by the receiver functions are superimposed to a background velocity model constrained by the dispersion velocities. In our first year of this project we will (i) generate 1D velocity models for open broadband seismic stations
Maouche, Naima; Ktari, Nadia; Bakas, Idriss; Fourati, Najla; Zerrouki, Chouki; Seydou, Mahamadou; Maurel, François; Chehimi, Mohammed Mehdi
2015-11-01
A surface acoustic wave sensor operating at 104 MHz and functionalized with a polypyrrole molecularly imprinted polymer has been designed for selective detection of dopamine (DA). Optimization of pyrrole/DA ratio, polymerization and immersion times permitted to obtain a highly selective sensor, which has a sensitivity of 0.55°/mM (≈ 550 Hz/mM) and a detection limit of ≈ 10 nM. Morphology and related roughness parameters of molecularly imprinted polymer surfaces, before and after extraction of DA, as well as that of the non imprinted polymer were characterized by atomic force microscopy. The developed chemosensor selectively recognized dopamine over the structurally similar compound 4-hydroxyphenethylamine (referred as tyramine), or ascorbic acid,which co-exists with DA in body fluids at a much higher concentration. Selectivity tests were also carried out with dihydroxybenzene, for which an unexpected phase variation of order of 75% of the DA one was observed. Quantum chemical calculations, based on the density functional theory, were carried out to determine the nature of interactions between each analyte and the PPy matrix and the DA imprinted PPy polypyrrole sensing layer in order to account for the important phase variation observed during dihydroxybenzene injection. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of Simulated Heat Waves on Cardiovascular Functions in Senile Mice
Directory of Open Access Journals (Sweden)
Xiakun Zhang
2014-08-01
Full Text Available The mechanism of the effects of simulated heat waves on cardiovascular disease in senile mice was investigated. Heat waves were simulated in a TEM1880 meteorological environment simulation chamber, according to a heat wave that occurred in July 2001 in Nanjing, China. Eighteen senile mice were divided into control, heat wave, and heat wave BH4 groups, respectively. Mice in the heat wave and heat wave BH4 groups were exposed to simulated heat waves in the simulation chamber. The levels of ET-1, NO, HSP60, SOD, TNF, sICAM-1, and HIF-1α in each group of mice were measured after heat wave simulation. Results show that heat waves decreased SOD activity in the myocardial tissue of senile mice, increased NO, HSP60, TNF, sICAM-1, and HIF-1α levels, and slightly decreased ET-1 levels, BH4 can relieve the effects of heat waves on various biological indicators. After a comprehensive analysis of the experiments above, we draw the followings conclusions regarding the influence of heat waves on senile mice: excess HSP60 activated immune cells, and induced endothelial cells and macrophages to secrete large amounts of ICAM-1, TNF-α, and other inflammatory cytokines, it also activated the inflammation response in the body and damaged the coronary endothelial cell structure, which increased the permeability of blood vessel intima and decreased SOD activity in cardiac tissues. The oxidation of lipoproteins in the blood increased, and large amounts of cholesterol were generated. Cholesterol penetrated the intima and deposited on the blood vessel wall, forming atherosclerosis and leading to the occurrence of cardiovascular disease in senile mice. These results maybe are useful for studying the effects of heat waves on elderly humans, which we discussed in the discussion chapter.
Directory of Open Access Journals (Sweden)
Badereddin Mohamad Al-Ali
2017-01-01
Full Text Available Introduction. To analyze the impact of radical prostatectomy (RPE on erectile function and lower urinary tract function in comparison to age-matched healthy men. Materials and Methods. Patients who underwent radical retropubic prostatectomy completed questionnaires containing the IIEF-5, the Bristol female LUTS questionnaire, and the International Prostate Symptom Score (IPSS. Results. Patients after RPE were included (n=363. Age-matched healthy men (n=363 were included. The mean IIEF-5 of patients aged 61–70 yrs after RPE was 10.4±6.6 versus 18.8±5.3 in the control cohort; the respective values for men aged 71–80 yrs after RPE were 7.2±6.5 versus 13.6±7.7 in the control cohort. Urinary incontinence after RPE was reported in 41.9% (61–70 years and 37.7% (71–80 versus 7.5% and 15.1% in the control cohort. The mean IPSS of patients after RPE aged 61–70 yrs was 5.0±4.4 versus 5.5±4.9 in the control cohort; the respective values for men aged 71–80 yrs were 6.0±4.9 versus 7.5±5.7 in the healthy cohort. Conclusions. The negative effect of radical prostatectomy on erectile and urinary incontinence remains substantial. The physiologically declining erectile and lower urinary tract function with ageing reduces the difference between healthy men and those after surgery. Healthy men have a higher IPSS presumably due to the presence of bladder outlet obstruction.
Directory of Open Access Journals (Sweden)
Tessa M van Leeuwen
Full Text Available BACKGROUND: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour. Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. METHODOLOGY/PRINCIPAL FINDINGS: First, in a free viewing functional magnetic resonance imaging (fMRI experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. CONCLUSIONS/SIGNIFICANCE: Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal
van Leeuwen, Tessa M.; Petersson, Karl Magnus; Hagoort, Peter
2010-01-01
Background In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. Methodology/Principal Findings First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Conclusions/Significance Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to
Rabanal-León, Walter A; Murillo-López, Juliana A; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro
2015-09-24
The high interest in lanthanide chemistry, and particularly in their luminescence, has been encouraged by the need of understanding the lanthanide chemical coordination and how the design of new luminescent materials can be affected by this. This work is focused on the understanding of the electronic structure, bonding nature, and optical properties of a set of lanthanide hexaaza macrocyclic complexes, which can lead to potential optical applications. Here we found that the DFT ground state of the open-shell complexes are mainly characterized by the manifold of low lying f states, having small HOMO-LUMO energy gaps. The results obtained from the wave function theory calculations (SO-RASSI) put on evidence the multiconfigurational character of their ground state and it is observed that the large spin-orbit coupling and the weak crystal field produce a strong mix of the ground and the excited states. The electron localization function (ELF) and the energy decomposition analysis (EDA) support the idea of a dative interaction between the macrocyclic ligand and the lanthanide center for all the studied systems; noting that, this interaction has a covalent character, where the d-orbital participation is evidenced from NBO analysis, leaving the f shell completely noninteracting in the chemical bonding. From the optical part we observed in all cases the characteristic intraligand (IL) (π-π*) and ligand to metal charge-transfer (LMCT) bands that are present in the ultraviolet and visible regions, and for the open-shell complexes we found the inherent f-f electronic transitions on the visible and near-infrared region.
Directory of Open Access Journals (Sweden)
Yang Zeng
Full Text Available Research on human immunology has been hindered by the lack of optimal small animal models, given that the protective immune responses of human and non-human species show significant differences. However, due to ethical constraints[1] and the high cost of clinical trials, it is urgent to improve the current animal models that can mimic faithfully human physiology, particularly the human immune system (HIS. HIS mice had been generated recently by engrafting human hematopoietic stem cells (hHSCs or human peripheral mononuclear cells (hPBMCs into highly immuno-deficient mice such as NSG, NOG or NRG mice. However, a major experimental drawback for studies using these models is the rapid onset of Graft-versus-Host Disease (GvHD. In the present study, we overcome this limitation by generating new immuno-deficient mice named "HUMAMICE" (HLA-A2+/+/DR1+/+/H-2-β2m-/-/IAβ-/-/Rag2-/-/IL2rγ-/-/Perf-/- mice, which expressed human HLA molecules instead of mouse MHC molecules (H-2, and whose immuno-deficient status was reversed by transferring functional HLA-matched PBMCs thus producing mice with an immuno-competent status with a functional human immune system. We showed that in this HLA-matched context, the hPBMC-transfer led to high lymphocytes engraftment rates without GvHD over three months in this novel mouse model. Furthermore, to evaluate the utility of the hPBMC-HUMAMICE, we immunized them with commercial vaccine of Hepatitis B virus (HBsAg, Hepvac@ which resulted in robust and reproducible production of high levels of HBsAg-specific antibodies, implying that both transferred T and B lymphocytes were functional in HUMAMICE. These responses are comparable to those observed in human clinical trials with this identical vaccine. In conclusion, these findings indicated that the HLA-matched-hPBMC-HUMAMICE represents a promising model for dissecting human immune responses in various human diseases, including infectious diseases, cancers and tumors, and to
Directory of Open Access Journals (Sweden)
Yunpeng Zhang
2015-01-01
Full Text Available Identification of miRNA-mRNA modules is an important step to elucidate their combinatorial effect on the pathogenesis and mechanisms underlying complex diseases. Current identification methods primarily are based upon miRNA-target information and matched miRNA and mRNA expression profiles. However, for heterogeneous diseases, the miRNA-mRNA regulatory mechanisms may differ between subtypes, leading to differences in clinical behavior. In order to explore the pathogenesis of each subtype, it is important to identify subtype specific miRNA-mRNA modules. In this study, we integrated the Ping-Pong algorithm and multiobjective genetic algorithm to identify subtype specific miRNA-mRNA functional regulatory modules (MFRMs through integrative analysis of three biological data sets: GO biological processes, miRNA target information, and matched miRNA and mRNA expression data. We applied our method on a heterogeneous disease, multiple myeloma (MM, to identify MM subtype specific MFRMs. The constructed miRNA-mRNA regulatory networks provide modular outlook at subtype specific miRNA-mRNA interactions. Furthermore, clustering analysis demonstrated that heterogeneous MFRMs were able to separate corresponding MM subtypes. These subtype specific MFRMs may aid in the further elucidation of the pathogenesis of each subtype and may serve to guide MM subtype diagnosis and treatment.
Munro, Kevin J; Puri, Reema; Bird, Judith; Smith, Mark
2016-01-01
Matching a prescription gain target at 60-65 dB SPL does not ensure audibility of lower input levels, nor does it mean the fitted frequency response slope is conducive to good sound quality. The aim of the present study was to evaluate the use of probe-microphone measurements to match target gain and slope, as a function of earmould style, frequency, and input level. The real-ear insertion gain was calculated for an input of 50, 65, and 80 dB SPL for the manufacturer's 'initial fit' (IF) settings and after adjustment to target in 49 and 51 open slim-tube and custom earmould fittings, respectively. One hundred adults with median age 74 years (range 32-93). Some 18%-67% of the IF settings were within 10 dB of the target gain but this increased to >85% after adjustment. Some 47%-71% of the IF settings were within 10 dB of the target slope but, with the exception of 2-4 kHz, this increased to >88% after adjustment. The results indicate that IF settings are inadequate, at least for the model of hearing aid used in the present study; however, significant discrepancies remained, even after adjustment.
Tesfaye, Meskerem Ruth
Microstrips are open waveguiding structures that are used in electronics. In this research, we compute the effective dielectric constants of open microstrip transmission lines using spheroidal wave functions and the spectral domain method. The microstrips considered are the dielectric filled and the ferrite filled microstrips. The magnetic field, electric field and current density relations for the boundary value problem associated with the open microstrip line are determined using Maxwell's equations. The field quantities and the boundary conditions are transformed to the spectral domain. The integro-differential equations that govern the electromagnetic fields are discretized using Galerkin's generalized moment method in the spectral domain. The effective dielectric constant is calculated for frequencies up to 100 GHZ for waveguides with dimensions on the order of a millimeter. An analysis of dielectric filled microstrips using the Fourier integrals was introduced by Denlinger. The results achieved were dependent on the assumed form of current distribution on the strip, which is not known a priori. Itoh and Mittra approached the problem by combining Galerkin's moment method with the spectral domain method. The difficulty of finding the current distribution exactly is avoided. Galerkin's moment method can be applied using any set of complete basis functions that meet the boundary conditions. If the choice of basis functions is not optimal more expansion terms will be needed to achieve the desired accuracy. This implies solving a larger size matrix. Itoh and Mittra used the Walsh functions to expand the current on the microstrip. The behavior of the current at the edges of the microstrip was not incorporated in the choice of basis functions. Itoh later used sinusoidal functions with edge conditions. The results were better than those achieved using the Walsh functions. Hechtman, et al. later used spheroidal wave functions. More accurate results were achieved and
Matching score based face recognition
Boom, B.J.; Beumer, G.M.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.
2006-01-01
Accurate face registration is of vital importance to the performance of a face recognition algorithm. We propose a new method: matching score based face registration, which searches for optimal alignment by maximizing the matching score output of a classifier as a function of the different
Analytical Derivation of Three Dimensional Vorticity Function for wave breaking in Surf Zone
Dutta, R.
2015-01-01
In this report, Mathematical model for generalized nonlinear three dimensional wave breaking equations was de- veloped analytically using fully nonlinear extended Boussinesq equations to encompass rotational dynamics in wave breaking zone. The three dimensional equations for vorticity distributions are developed from Reynold based stress equations. Vorticity transport equations are also developed for wave breaking zone. This equations are basic model tools for numerical simulation of surf zon...
DEFF Research Database (Denmark)
Markussen, Troels; Kristensen, Philip Trøst; Tromborg, Bjarne
2006-01-01
Models of carrier dynamics in quantum dots rely strongly on adequate descriptions of the carrier wave functions. In this work we numerically solve the one-band effective mass Schrodinger equation to calculate the capture times of phonon-mediated carrier capture into self-assembled quantum dots...
Estienne, B.; Bernevig, B.A.; Santachiara, R.
2011-01-01
We consider the quasihole wave functions of the non-Abelian Read-Rezayi quantum-Hall states which are given by the conformal blocks of the minimal model WAk−1(k+1,k+2) of the WAk−1 algebra. By studying the degenerate representations of this conformal field theories, we derive a second-order
2007-01-01
black). 13 Comparison of the Sandvol et al. (1998) crustal thicknesses (circles) and 22 the crustal thicknesses inferred from the joint inversion... lithospheric structure of that region and, therefore, originating new studies: Sandvol et al. (1998) computed receiver functions from P-wave...in the Arabian peninsula, Rodgers et al. (1999) estimated lithospheric velocity structure by modeling regional waveforms, and Mokhtar et al. (2001
López-Rosa, S.; Esquivel, R. O.; Plastino, A. R.; Dehesa, J. S.
2015-09-01
In this work we have performed state-of-the-art configuration-interaction (CI) calculations to determine the linear and von Neumann entanglement entropies for the helium-like systems with varying nuclear charge Z in the range 1≤slant Z≤slant 10. The focus of the work resides on determining accurate entanglement values for 2-electron systems with the lowest computational cost through compact CI-wave functions. Our entanglement results for the helium atom fully agree with the results obtained with higher quality wave functions of the Kinoshita type (Dehesa [5]). We find that the correlation energy is linearly related to the entanglement measures associated with the linear and von Neumann entropies of the single-particle reduced density matrizes, which sheds new light on the physical implications of entanglement in helium-like systems. Moreover, we report CI-wave-function-based benchmark results for the entanglement values for all members of the helium isoelectronic series with an accuracy similar to that of Kinoshita-type wave functions. Finally, we give parametric expressions of the linear and von Neumann entanglement measures for two-electron systems as Z varies from 1 to 10.
Bertelli, N.; Valeo, E. J.; Green, D. L.; Gorelenkova, M.; Phillips, C. K.; Podestà, M.; Lee, J. P.; Wright, J. C.; Jaeger, E. F.
2017-05-01
At the power levels required for significant heating and current drive in magnetically-confined toroidal plasma, modification of the particle distribution function from a Maxwellian shape is likely (Stix 1975 Nucl. Fusion 15 737), with consequent changes in wave propagation and in the location and amount of absorption. In order to study these effects computationally, both the finite-Larmor-radius and the high-harmonic fast wave (HHFW), versions of the full-wave, hot-plasma toroidal simulation code TORIC (Brambilla 1999 Plasma Phys. Control. Fusion 41 1 and Brambilla 2002 Plasma Phys. Control. Fusion 44 2423), have been extended to allow the prescription of arbitrary velocity distributions of the form f≤ft({{v}\\parallel},{{v}\\bot},\\psi,θ \\right) . For hydrogen (H) minority heating of a deuterium (D) plasma with anisotropic Maxwellian H distributions, the fractional H absorption varies significantly with changes in parallel temperature but is essentially independent of perpendicular temperature. On the other hand, for HHFW regime with anisotropic Maxwellian fast ion distribution, the fractional beam ion absorption varies mainly with changes in the perpendicular temperature. The evaluation of the wave-field and power absorption, through the full wave solver, with the ion distribution function provided by either a Monte-Carlo particle and Fokker-Planck codes is also examined for Alcator C-Mod and NSTX plasmas. Non-Maxwellian effects generally tend to increase the absorption with respect to the equivalent Maxwellian distribution.
Hoots, C. R.; Schmandt, B.; Clayton, R. W.; Dougherty, S. L.; Hansen, S. M.
2014-12-01
Past seismic imaging studies of the Isabella anomaly in Southern California lacked resolution to distinguish between the two dominating hypotheses for its origin: a fossil slab origin or a foundering lithospheric root of the Sierra Nevada volcanic arc. To definitively distinguish the origin of the anomaly as one, or neither, of these possibilities is important in the understanding of the evolution of continental arcs and the process of subduction termination. To do this, we deployed an array of 44 broadband seismometers from the Isabella anomaly to the coast at latitude 36°N, starting in December 2013. The array has a station spacing of ~7 km spacing filling a gap between the southern and northern California permanent seismic networks (NCSN and SCSN). The array will continue to collect data until summer 2015. We will present preliminary surface wave tomography results using empirical interstation green's functions derived from ambient seismic noise recorded by more than 500 stations that currently or previously surround our array. Initial Ps receiver function images from common conversion point stacking will also be presented. We also use local earthquakes to model the shape and velocity of the Central Valley, as this will be important in correcting the tomography and receiver function images.We also deployed a dense array of short period stations in Peachtree Valley, where the broadband array crossed the San Andreas Fault (SAF). This network will be used to determine the location and level of seismicity on a segment of the SAF where it is creeping.This first batch of results from our broadband seismic experiment should provide new insight into how far the basaltic crust of the Monterey microplate extends inland beneath California and whether the Isabella anomaly is connected to North America or Pacific lithosphere.
Receiver function analysis and preliminary body wave tomography of the MACOMO network in Madagascar
Pratt, M. J.; Wysession, M. E.; Wiens, D. A.; Nyblade, A.; Aleqabi, G. I.; Shore, P.; Rambolamana, G.; Sy Tanjona Andriampenomanana ny Ony, F.; Rakotondraibe, T.
2013-12-01
We present results from a set of seismological studies of the continental island of Madagascar using new seismic data from the NSF-funded MACOMO (MAdagascar, COmores, and MOzambique) IRIS PASSCAL broadband seismometer array. MACOMO involved the deployment during 2011-2013 of 26 broadband seismometers in Madagascar and 6 seismometers in Mozambique, providing the first seismic imaging across the world's 4th-largest island. We present preliminary crustal structure variations from receiver function analyses and body wave tomography results. We calculate radial receiver functions for all Madagascar stations and use the weighted linear regression methodology of Herrmann and Ammon [2002] to invert for shear velocity. Upper mantle and crustal structures from the receiver function analyses are used to help determine starting models for the teleseismic travel-time tomography. The tectonic structure of Madagascar is generally divided into four crustal blocks. Initial seismic imaging shows that the Archean Antongil block that runs along the east of the island has the thickest crust (>40 km) and three Proterozoic terranes that make up the central highlands and are bounded by fault and shear zones are closer to the average crustal thickness (35 km). There has been late Cenozoic intraplate volcanism in northern and central Madagascar (as recently as 1 million years ago), and different hypotheses for its origin will be evaluated by the preliminary results from the three different seismic studies. Complete analyses will be done incorporating seismic data from simultaneous and complementary array of both land- and ocean-based seismometers from French and German deployments.
Determination of Transmission Line Impedance Matching Parameters
African Journals Online (AJOL)
In this work, transmission line impedance matching parameters were determined in Ugbowo ED0024GI Global System for Mobile Communication (GSM) base station in Benin City, Edo State, Nigeria. The transmission line impedance matching parameter viz voltage standing wave ratio was measured with the aid of the ...
Sugisaki, Kenji; Yamamoto, Satoru; Nakazawa, Shigeaki; Toyota, Kazuo; Sato, Kazunobu; Shiomi, Daisuke; Takui, Takeji
2016-08-18
Quantum computers are capable to efficiently perform full configuration interaction (FCI) calculations of atoms and molecules by using the quantum phase estimation (QPE) algorithm. Because the success probability of the QPE depends on the overlap between approximate and exact wave functions, efficient methods to prepare accurate initial guess wave functions enough to have sufficiently large overlap with the exact ones are highly desired. Here, we propose a quantum algorithm to construct the wave function consisting of one configuration state function, which is suitable for the initial guess wave function in QPE-based FCI calculations of open-shell molecules, based on the addition theorem of angular momentum. The proposed quantum algorithm enables us to prepare the wave function consisting of an exponential number of Slater determinants only by a polynomial number of quantum operations.
Daniels, Alan H; Koller, Heiko; Hiratzka, Shannon L; Mayer, Michael; Meier, Oliver; Contag, Alec Gabriel; Eltorai, Adam E M; Hiratzka, Jayme; Kojo Hamilton, D; Shaffrey, Christopher I; Smith, Justin S; Bess, Shay; Klineberg, Eric O; Ames, Christopher P; Lafage, Virginie; Line, Breton; Schwab, Frank J; Hart, Robert A; Group, International Spine Study
2017-06-01
Controversy persists as to whether to end multilevel thoracolumbar fusions caudally at L5 or S1. Some argue that stopping at L5 may preserve greater function, but there are few data comparing functional limitations due to lumbar stiffness in patients with fusion to L5 versus S1. The aim of this study was to evaluate whether patients undergoing multilevel thoracolumbar fusions with an L5 caudal endpoint have a better lumbosacral function than patients with an S1 caudal endpoint. Patients undergoing successful thoracolumbar fusion of 5 or more levels to L5 or S1, with solid fusion at 2 year follow-up, were examined from a single European center in addition to a multi-center North American database of 237 patients. In total, 40 patients with a distal stopping point of L5 were matched with a subset of 40 patients with a distal endpoint of S1 ± pelvic fixation. The L5 and S1 groups were matched for the final Oswestry Disability Index (ODI), Sagittal Vertical Axis (SVA C7-S1), number of fusion levels, and age. Impacts of lumbar stiffness on function as measured by the Lumbar Stiffness Disability Index (LSDI) were compared using the conditional logistic regression. After matching, there was no significant difference between the S1 and L5 groups for the final ODI (29.22 ± 21.6 for S1 versus 29.21 ± 21.7 for L5; p = 0.98), SVA (29.5 ± 40.3 mm for S1 versus 33.7 ± 37.1 mm for L5; p = 0.97), mean age (61.6 ± 11.0 years for S1 versus 58.3 ± 12.6 years for L5; p = 0.23), and number of fusion levels (9.7 ± 3.3 levels for S1 versus 9.0 ± 3 levels for L5; p = 0.34). The final 2-year postoperative LSDI scores were not significantly different between the S1 group (28.08 ± 21.47) and L5 group (29.21 ± 21.66) (hazard ratio 0.99, 95 % CI 0.97-1.03, p = 0.81). The analysis of patients with multilevel thoracolumbar fusions demonstrated that after minimum 2 year follow-up, self-reported functional impacts of lumbar stiffness were not
Morelli, Luca; Di Franco, Gregorio; Guadagni, Simone; Rossi, Leonardo; Palmeri, Matteo; Furbetta, Niccolò; Gianardi, Desirée; Bianchini, Matteo; Caprili, Giovanni; D'Isidoro, Cristiano; Mosca, Franco; Moglia, Andrea; Cuschieri, Alfred
2017-07-21
Robotic rectal resection with da Vinci Si has some technical limitations, which could be overcome by the new da Vinci Xi. We compare short-term surgical and functional outcomes following robotic rectal resection with total mesorectal excision for cancer, with the da Vinci Xi (Xi-RobTME group) and the da Vinci Si (Si-RobTME group). The first consecutive 30 Xi-RobTME were compared with a Si-RobTME control group of 30 patients, selected using a one-to-one case-matched methodology from our prospectively collected Institutional database, comprising all cases performed between April 2010 and September 2016 by a single surgeon. Perioperative outcomes were compared. The impact of minimally invasive TME on autonomic function and quality of life was analyzed with specific questionnaires. The docking and overall operative time were shorter in the Xi-RobTME group (p robotic approach with complete splenic flexure mobilization was used in 30/30 (100%) of the Xi-RobTME cases and in 7/30 (23%) of the Si-RobTME group (p 25 kg/m2 was necessary in ten patients (45 vs. 0%, p Vinci Xi seem to be mainly associated with a shorter docking and operative time and with superior ability to perform a fully-robotic approach. Clinical and functional outcomes seem not to be improved, with the introduction of the new Xi platform.
Multifractality of wave functions on a Cayley tree: From root to leaves
Sonner, M.; Tikhonov, K. S.; Mirlin, A. D.
2017-12-01
We explore the evolution of wave-function statistics on a finite Bethe lattice (Cayley tree) from the central site ("root") to the boundary ("leaves"). We show that the eigenfunction moments Pq=N〈|ψ | 2 q(i ) 〉 exhibit a multifractal scaling Pq∝N-τq with the volume (number of sites) N at N →∞ . The multifractality spectrum τq depends on the strength of disorder and on the parameter s characterizing the position of the observation point i on the lattice. Specifically, s =r /R , where r is the distance from the observation point to the root, and R is the "radius" of the lattice. We demonstrate that the exponents τq depend linearly on s and determine the evolution of the spectrum with increasing disorder, from delocalized to the localized phase. Analytical results are obtained for the n -orbital model with n ≫1 that can be mapped onto a supersymmetric σ model. These results are supported by numerical simulations (exact diagonalization) of the conventional (n =1 ) Anderson tight-binding model.
Fourier transforms of single-particle wave functions in cylindrical coordinates
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Rizea, M. [National Institute of Physics and Nuclear Engineering, ' ' Horia Hulubei' ' , Bucharest (Romania); Carjan, N. [National Institute of Physics and Nuclear Engineering, ' ' Horia Hulubei' ' , Bucharest (Romania); Joint Institute for Nuclear Research, FLNR, Dubna, Moscow Region (Russian Federation); University of Bordeaux, CENBG, Gradignan (France)
2016-12-15
A formalism and the corresponding numerical procedures that calculate the Fourier transform of a single-particle wave function defined on a grid of cylindrical (ρ, z) coordinates is presented. Single-particle states in spherical and deformed nuclei have been chosen in view of future applications in the field of nuclear reactions. Bidimensional plots of the probability that the nucleon's momentum has a given value K = √(k{sub ρ}{sup 2}+k{sub z}{sup 2}) are produced and from them the K -distributions are deduced. Three potentials have been investigated: (a) a sharp surface spherical well (i.e., of constant depth), (b) a spherical Woods-Saxon potential (i.e., diffuse surface) and (c) a deformed potential of Woods-Saxon type. In the first case the momenta are as well defined as allowed by the uncertainty principle. Depending on the state, their distributions have up to three separated peaks as a consequence of the up to three circular ridges of the bidimensional probabilities plots. In the second case the diffuseness allows very low momenta to be always populated thus creating tails towards the origin (K = 0). The peaks are still present but not well separated. In the third case the deformation transforms the above mentioned circular ridges into ellipses thus spreading the K-values along them. As a consequence the K-distributions have only one broad peak. (orig.)
Inflation including collapse of the wave function: the quasi-de Sitter case
Energy Technology Data Exchange (ETDEWEB)
Leon, Gabriel [Universidad de Buenos Aires, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Landau, Susana J. [Universidad de Buenos Aires y IFIBA, CONICET, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Piccirilli, Maria Pia [Universidad Nacional de La Plata, Grupo de Astrofisica, Relatividad y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Pcia de Buenos Aires (Argentina)
2015-08-15
The precise physical mechanism describing the emergence of the seeds of cosmic structure from a perfect isotropic and homogeneous universe has not been fully explained by the standard version of inflationary models. To handle this shortcoming, D. Sudarsky and collaborators have developed a proposal: the self-induced collapse hypothesis. In this scheme, the objective collapse of the inflaton wave function is responsible for the emergence of inhomogeneity and anisotropy at all scales. In previous papers, the proposal was developed with an almost exact de Sitter space-time approximation for the background that led to a perfect scale-invariant power spectrum. In the present article, we consider a full quasi-de Sitter expansion and calculate the primordial power spectrum for three different choices of the self-induced collapse. The consideration of a quasi-de Sitter background allows us to distinguish departures from an exact scale-invariant power spectrum that are due to the inclusion of the collapse hypothesis. These deviations are also different from the prediction of standard inflationary models with a running spectral index. A comparison with the primordial power spectrum and the CMB temperature fluctuation spectrum preferred by the latest observational data is also discussed. From the analysis performed in this work, it follows that most of the collapse schemes analyzed in this paper are viable candidates to explain the present observations of the CMB fluctuation spectrum. (orig.)
A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function.
Keijsers, J M T; Leguy, C A D; Huberts, W; Narracott, A J; Rittweger, J; van de Vosse, F N
2015-07-01
The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial-to-deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one-dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery-vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.
Cao, Hujia; Ma, Junliang; Huang, Lin; Qin, Haiyan; Meng, Renyang; Li, Yang; Peng, Xiaogang
2016-12-07
Single-molecular spectroscopy reveals that photoluminescence (PL) of a single quantum dot blinks, randomly switching between bright and dim/dark states under constant photoexcitation, and quantum dots photobleach readily. These facts cast great doubts on potential applications of these promising emitters. After ∼20 years of efforts, synthesis of nonblinking quantum dots is still challenging, with nonblinking quantum dots only available in red-emitting window. Here we report synthesis of nonblinking quantum dots covering most part of the visible window using a new synthetic strategy, i.e., confining the excited-state wave functions of the core/shell quantum dots within the core quantum dot and its inner shells (≤ ∼5 monolayers). For the red-emitting ones, the new synthetic strategy yields nonblinking quantum dots with small sizes (∼8 nm in diameter) and improved nonblinking properties. These new nonblinking quantum dots are found to be antibleaching. Results further imply that the PL blinking and photobleaching of quantum dots are likely related to each other.
Classical Branch Structure from Spatial Redundancy in a Many-Body Wave Function
Riedel, C. Jess
2017-03-01
When the wave function of a large quantum system unitarily evolves away from a low-entropy initial state, there is strong circumstantial evidence it develops "branches": a decomposition into orthogonal components that is indistinguishable from the corresponding incoherent mixture with feasible observations. Is this decomposition unique? Must the number of branches increase with time? These questions are hard to answer because there is no formal definition of branches, and most intuition is based on toy models with arbitrarily preferred degrees of freedom. Here, assuming only the tensor structure associated with spatial locality, I show that branch decompositions are highly constrained just by the requirement that they exhibit redundant local records. The set of all redundantly recorded observables induces a preferred decomposition into simultaneous eigenstates unless their records are highly extended and delicately overlapping, as exemplified by the Shor error-correcting code. A maximum length scale for records is enough to guarantee uniqueness. Speculatively, objective branch decompositions may speed up numerical simulations of nonstationary many-body states, illuminate the thermalization of closed systems, and demote measurement from fundamental primitive in the quantum formalism.
El-Bennich, B.; Kloet, W. M.; Loiseau, B.
2003-07-01
We use a distorted wave approximation approach which includes 3P0 and 3S1 quark-antiquark annihilation mechanisms to reproduce the data set from LEAR on bar pp -> π ^ + π ^ - in the range from 360 to 1550 MeV/c. Improvements of the model are sought by implementing final-state interactions of the pions and by observing that the annihilation is too short-ranged in earlier attempts to describe the data. While the former improvement is due to to the final-state ππ wave functions solely, the latter one originates from quark wave functions for proton, antiproton, and pions with radii slightly larger than the respective measured charge radii. This increase in hadron radius, as compared with typically much smaller radii used before in the quark model, increases the annihilation range and thereby the amplitudes for J ≥ 2 are much higher. Finally, given the very high kinetic energy of the final pions, we investigate the role of relativistic corrections in the pion wave functions when boosted into the center-of-mass frame.
Propagation of elastic waves in an anisotropic functionally graded hollow cylinder in vacuum.
Baron, Cécile
2011-02-01
As a non-destructive, non-invasive and non-ionizing evaluation technique for heterogeneous media, the ultrasonic method is of major interest in industrial applications but especially in biomedical fields. Among the unidirectionally heterogeneous media, the continuously varying media are a particular but widespread case in natural materials. The first studies on laterally varying media were carried out by geophysicists on the Ocean, the atmosphere or the Earth, but the teeth, the bone, the shells and the insects wings are also functionally graded media. Some of them can be modeled as planar structures but a lot of them are curved media and need to be modeled as cylinders instead of plates. The present paper investigates the influence of the tubular geometry of a waveguide on the propagation of elastic waves. In this paper, the studied structure is an anisotropic hollow cylinder with elastic properties (stiffness coefficients c(ij) and mass density ρ) functionally varying in the radial direction. An original method is proposed to find the eigenmodes of this waveguide without using a multilayered model for the cylinder. This method is based on the sextic Stroh's formalism and an analytical solution, the matricant, explicitly expressed under the Peano series expansion form. This approach has already been validated for the study of an anisotropic laterally-graded plate (Baron et al., 2007; Baron and Naili, 2010) [6,5]. The dispersion curves obtained for the radially-graded cylinder are compared to the dispersion curves of a corresponding laterally-graded plate to evaluate the influence of the curvature. Preliminary results are presented for a tube of bone in vacuum modelling the in vitro conditions of bone strength evaluation. Copyright © 2010 Elsevier B.V. All rights reserved.
Grötzinger, Stefan W.
2014-04-07
Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile\\'s genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available
Directory of Open Access Journals (Sweden)
Stefan Wolfgang Grötzinger
2014-04-01
Full Text Available Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs and poor homology of novel extremophile’s genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the INDIGO data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes may translate into false positives when searching for specific functions. The Profile & Pattern Matching (PPM strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO-terms (which represent enzyme function profiles and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern. The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2,577 E.C. numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from 6 different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter and PROSITE IDs (pattern filter. Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns are present. Scripts for annotation, as well as for the PPM algorithm, are available through the INDIGO website.
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Branch, Darren W.
2008-05-01
Recently, the generalized method for calculation of the 16-element Green's function for analysis of surface acoustic waves has proven crucial to develop more sophisticated transducers. The generalized Green's function provides a precise relationship between the acoustic stresses and electric displacement on the three mechanical displacements and electric potential. This generalized method is able to account for mass loading effects which is absent in the effective permittivity approach. However, the calculation is numerically intensive and may lead to numerical instabilities when solving for both the eigenvalues and eigenvectors simultaneously. In this work, the general eigenvalue problem was modified to eliminate the numerical instabilities in the solving procedure. An algorithm is also presented to select the proper eigenvalues rapidly to facilitate analysis for all types of acoustic propagation. The 4 x 4 Green's functions and effective permittivities were calculated for materials supporting Rayleigh, leaky, and leaky longitudinal waves as demonstration of the method.
Wess, Othmar
2005-04-01
Since 1980 shock waves have proven effective in the field of extracorporeal lithotripsy. More than 10 years ago shock waves were successfully applied for various indications such as chronic pain, non-unions and, recently, for angina pectoris. These fields do not profit from the disintegration power but from stimulating and healing effects of shock waves. Increased metabolism and neo-vascularization are reported after shock wave application. According to C. J. Wang, a biological cascade is initiated, starting with a stimulating effect of physical energy resulting in increased circulation and metabolism. Pathological memory of neural control patterns is considered the reason for different pathologies characterized by insufficient metabolism. This paper presents a neural model for reorganization of pathological reflex patterns. The model acts on associative memory functions of the brain based on modification of synaptic junctions. Accordingly, pathological memory effects of the autonomous nervous system are reorganized by repeated application of shock waves followed by development of normal reflex patterns. Physiologic control of muscle and vascular tone is followed by increased metabolism and tissue repair. The memory model may explain hyper-stimulation effects in pain therapy.
Directory of Open Access Journals (Sweden)
Nina K. Palmen
2014-11-01
Full Text Available The diagnosis of Legg-Calvé-Perthes disease (LCPD has a considerable influence on the daily life of the patients with restrictions in their leisure time activities. This might influence their mood. Until now this aspect of the disease has been neglected. Therefore the objective of the study was to evaluate the health related quality of life (HRQoL of children with severe LCPD who had an extensive surgery with pelvic/femoral osteotomy. The KIDSCREEN-10 and the modified Modified Harris Hip Score (mHHS-questionnaire were administered to 17 children (16 boys and 1 girl aged 5 to 11 years at the time of surgery. Analyses of mHHS were made preoperatively and at the time of the follow-up examination at least 2 years postoperatively. KIDSCREEN-analyses were made postoperatively. The follow-up results were compared to an age-matched normal control group. Correlations were computed between KIDSCREEN-10 and mHHS pre- and post-operatively. The postoperative calculated KIDSCREEN-10-T-value [70.2 (SD 12.7] was higher than the mean T-value of the control-group [56.6 (SD 10.4]. The mHHS improved from 54.4 (SD 19.9 to a score of 99.5 (SD 1.5 postoperatively. A strong correlation was found between the preoperative mHHS and the postoperative KIDSCREEN-10- T-value (Spearman’s-rho 0.67, P=0.003. After containment improving surgery and a mean follow-up period of 4.2 years the HRQoL-status is even better compared with a healthy age-matched control group. As well an excellent clinical function could be achieved.
Liu, Ru-Fen; Franzese, Christina A; Malek, Ryan; Żuchowski, Piotr S; Ángyán, János G; Szczȩśniak, Małgorzata M; Chałasiński, Grzegorz
2011-08-09
The aurophilic interaction is examined in three model systems Au2((3)Σg(+)), (AuH)2, and (HAuPH3)2 which contain interactions of pairs of the Au centers in the oxidation state (I). Several methods are employed ranging from wave function theory-based (WFT) approaches to symmetry-adapted perturbation theory (SAPT) and range-separated hybrid (RSH) density functional theory (DFT) methods. The most promising and accurate approach consists of a combination of the DFT and WFT approaches in the RSH framework. In this combination the short-range DFT handles the slow convergence of the correlation cusp, whereas the long-range WFT is best suited for the long-range correlation. Of the three tested RSH DFT methods, the one which uses a short-range exchange functional based on the Ernzerhof-Perdew exchange hole model with a range-separation parameter of 0.4 bohr(-1) seems to be the best candidate for treatment of gold. In combination with the long-range coupled cluster singles, doubles, and noniterative triples [CCSD(T)] treatment it places the strength of aurophilic bonding in (HAuPH3)2 at 5.7 kcal/mol at R = 3.09 Å. This value is somewhat larger than our best purely WFT result based on CCSD(T), 4.95 kcal/mol (R = 3.1 Å), and considerably smaller than the Hartree-Fock+dispersion value of 7.4 kcal/mol (R = 2.9 Å). The 5.7 kcal/mol estimate fits reasonably well within the prediction of the empirical relationship proposed by Schwerdtfeger et al. (J. Am. Chem. Soc.1998, 120, 6587). A direct computation of dispersion energy, including exchange corrections, results in values of ca. -9 kcal/mol for Au2((3)Σg(+)) and (AuH)2 and -13 kcal/mol for (HAuPH3)2 at the distance of a typical aurophilic bond, R = 3.0 Å.
Lee, Ha Youn; Choi, Sun Mi; Lee, Jinwoo; Park, Young Sik; Lee, Chang-Hoon; Kim, Deog Kyeom; Lee, Sang-Min; Yoon, Ho Il; Yim, Jae-Joon; Kim, Young Whan; Han, Sung Koo; Yoo, Chul-Gyu
2015-01-01
Tiotropium failed to slow the annual rate of forced expiratory volume in 1 second (FEV1) decline in chronic obstructive pulmonary disease (COPD) patients with pulmonary tuberculosis, pulmonary resection, or long-term use of a short-acting muscarinic antagonist. The annual lung function decline in patients using tiotropium was compared with that in patients not using the drug. Of the 587 patients enrolled in the study, 257 took tiotropium. Following propensity score matching, 404 patients were included in the analysis. The mean annual rate of post-BD FEV1 decline was 23.9 (tiotropium) and 22.5 (control) mL/yr (P=0.86); corresponding pre-BD values were 30.4 and 21.9 mL/yr (P=0.31), respectively. Mean annual rate of post-BD FVC decline was 55.1 (tiotropium) and 43.5 (control) mL/yr (P=0.33); corresponding pre-BD values were 37.1 and 33.3 mL/yr (P=0.13). Therefore, tiotropium does not reduce the rate of lung function decline in COPD patients with FEV1≥70%.
Chun, Kin-Yip; Zhu, Tianfei; West, Gordon F.
1991-07-01
We report here the results of a comprehensive seismic attenuation investigation along the paths connecting Canada's Yellowknife seismic array (YKA) with seven active nuclear explosion testing areas. The data consist of more than 600 explosion-generated teleseismic P wave records. A dual time-frequency averaging technique is used to take advantage of the array recording characteristics without the drawback of the conventional beam-forming, excessive annihilation of high-frequency signal energies. The dual averaging technique, deployed in conjunction with a multiwindow spectral analysis method, yields smooth amplitude spectra whose falloff at high frequencies suffers little from spectral leakage due to the familiar presence of a prominent low-frequency plateau. Measured in terms of t*, the highest attenuation (0.66 s) is found along the path which originates from the Tuamotu test area; somewhat less attenuating are the two paths which depart from the Pahute Mesa (0.59 s) and Yucca Flat (0.50 s) nuclear test areas, both located within the U.S. Nevada Test Site. We find t* for these three paths to be substantially (up to 0.21 s) higher than recently published estimates (e.g., Der et al., 1985). We attribute these disparities largely to differences in spectral leakage control capability between the conventional single window and the improved multiwindow spectral analysis methods. The least attenuating paths all originate from the Soviet test areas: Novaya Zemlya (NZ), west Kazakhstan, Degelen Mountain (DM), and Shagan River (SR). The last two of these test areas, DM and SR, are both located in east Kazakhstan. The P wave signatures of the Soviet explosions are rich in high-frequency (>4.5 Hz) energies, and the YKA data (0.5-8.0 Hz) support a frequency-dependent t* whose value at high frequencies (>4.5 Hz) is as small as 0.17 s. To gain a grasp of the ramifications of the t* disparity between the multiple-window and the single-window results, we have compared explosion
Experimental and Simulative Study on Accumulator Function in The Process of Wave Energy Conversion
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Zhang Wei
2016-09-01
Full Text Available In this paper, a floating-buoy wave energy converter using hydrostatic transmission system is studied. The entire work progress of wave energy power generation device is introduced, and the hydraulic transmission principles are emphasized through the simulation to verify the feasibility of design principle of hydraulic transmission system. The mathematical model of the accumulator is established and applied in the AMEsim simulation. The simulation results show that the accumulator plays an important role in the wave power hydraulic transmission system and that the correct configuration of accumulator parameters can improve the rapidity and stability of the system work. Experimental results are compared with the simulation results to validate the correctness of the simulation results. This would provide a valuable reference to the optimal design of wave power generation.
National Research Council Canada - National Science Library
Ding, Yi; Liao, Qingliang; Liu, Shuo; Guo, Huijing; Sun, Yihui; Zhang, Guangjie; Zhang, Yue
2016-01-01
...) as a novel type of electromagnetic wave (EW) absorbing materials was successfully prepared by a three-step chemical method including hydrothermal synthesis, annealing process and mixing with paraffin...
Plasser, Felix; Mewes, Stefanie A; Dreuw, Andreas; González, Leticia
2017-11-14
High-level multireference computations on electronically excited and charged states of tetracene are performed, and the results are analyzed using an extensive wave function analysis toolbox that has been newly implemented in the Molcas program package. Aside from verifying the strong effect of dynamic correlation, this study reveals an unexpected critical influence of the atomic orbital basis set. It is shown that different polarized double-ζ basis sets produce significantly different results for energies, densities, and overall wave functions, with the best performance obtained for the atomic natural orbital (ANO) basis set by Pierloot et al. Strikingly, the ANO basis set not only reproduces the energies but also performs exceptionally well in terms of describing the diffuseness of the different states and of their attachment/detachment densities. This study, thus, not only underlines the fact that diffuse basis functions are needed for an accurate description of the electronic wave functions but also shows that, at least for the present example, it is enough to include them implicitly in the contraction scheme.
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Kato, Tsuyoshi; Ide, Yoshihiro; Yamanouchi, Kaoru [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo Bunkyo-ku, Tokyo, 113-0033 (Japan)
2015-12-31
We first calculate the ground-state molecular wave function of 1D model H{sub 2} molecule by solving the coupled equations of motion formulated in the extended multi-configuration time-dependent Hartree-Fock (MCTDHF) method by the imaginary time propagation. From the comparisons with the results obtained by the Born-Huang (BH) expansion method as well as with the exact wave function, we observe that the memory size required in the extended MCTDHF method is about two orders of magnitude smaller than in the BH expansion method to achieve the same accuracy for the total energy. Second, in order to provide a theoretical means to understand dynamical behavior of the wave function, we propose to define effective adiabatic potential functions and compare them with the conventional adiabatic electronic potentials, although the notion of the adiabatic potentials is not used in the extended MCTDHF approach. From the comparison, we conclude that by calculating the effective potentials we may be able to predict the energy differences among electronic states even for a time-dependent system, e.g., time-dependent excitation energies, which would be difficult to be estimated within the BH expansion approach.
Ammirati, Jean-Baptiste; Alvarado, Patricia; Beck, Susan
2015-07-01
In the central Andes, the Nazca plate displays large along strike variations in dip with a near horizontal subduction angle between 28 and 32°S referred to the Pampean flat slab segment. The upper plate above the Pampean flat slab has high rates of crustal seismicity and active basement cored uplifts. The SIEMBRA experiment, a 43-broad-band-seismic-station array was deployed to better characterize the Pampean flat slab region around 31°S. In this study, we explore the lithospheric structure above the flat slab as a whole and its relation to seismicity. We use the SIEMBRA data to perform a joint inversion of teleseismic receiver functions and Rayleigh wave phase velocity dispersion to constrain the shear wave velocity variations in the lithosphere. Our joint inversion results show: (1) the presence of several upper-plate mid-crustal discontinuities and their lateral extent that are probably related to the terrane accretion history; (2) zones of high shear wave velocity in the upper-plate lower crust associated with a weak Moho signal consistent with the hypothesis of partial eclogitization in the lower crust; (3) the presence of low shear-wave velocities at ˜100 km depth interpreted as the subducting oceanic crust. Finally, in order to investigate the relation of the lithospheric structure to seismicity, we determine an optimal velocity-depth model based on the joint inversion results and use it to perform regional moment tensor inversions (SMTI) of crustal and slab earthquakes. The SMTI for 18 earthquakes that occurred between 2007 and 2009 in the flat slab region below Argentina, indicates systematically shallower focal depths for slab earthquakes (compared with inversions using previous velocity models). This suggests that the slab seismicity is concentrated mostly between 90 and 110 km depths within the subducting Nazca plate's oceanic crust and likely related to dehydration. In addition, the slab earthquakes exhibit extensional focal mechanisms suggesting
Variability In Long-Wave Runup as a Function of Nearshore Bathymetric Features
Energy Technology Data Exchange (ETDEWEB)
Dunkin, Lauren McNeill [Texas A & M Univ., College Station, TX (United States)
2010-05-01
Beaches and barrier islands are vulnerable to extreme storm events, such as hurricanes, that can cause severe erosion and overwash to the system. Having dunes and a wide beach in front of coastal infrastructure can provide protection during a storm, but the influence that nearshore bathymetric features have in protecting the beach and barrier island system is not completely understood. The spatial variation in nearshore features, such as sand bars and beach cusps, can alter nearshore hydrodynamics, including wave setup and runup. The influence of bathymetric features on long-wave runup can be used in evaluating the vulnerability of coastal regions to erosion and dune overtopping, evaluating the changing morphology, and implementing plans to protect infrastructure. In this thesis, long-wave runup variation due to changing bathymetric features as determined with the numerical model XBeach is quantified (eXtreme Beach behavior model). Wave heights are analyzed to determine the energy through the surfzone. XBeach assumes that coastal erosion at the land-sea interface is dominated by bound long-wave processes. Several hydrodynamic conditions are used to force the numerical model. The XBeach simulation results suggest that bathymetric irregularity induces significant changes in the extreme long-wave runup at the beach and the energy indicator through the surfzone.
Holfeld, Johannes; Zimpfer, Daniel; Albrecht-Schgoer, Karin; Stojadinovic, Alexander; Paulus, Patrick; Dumfarth, Julia; Thomas, Anita; Lobenwein, Daniela; Tepeköylü, Can; Rosenhek, Raphael; Schaden, Wolfgang; Kirchmair, Rudolf; Aharinejad, Seyedhossein; Grimm, Michael
2016-12-01
Previously we have shown that epicardial shock-wave therapy improves left ventricular ejection fraction (LVEF) in a rat model of myocardial infarction. In the present experiments we aimed to address the safety and efficacy of epicardial shock-wave therapy in a preclinical large animal model and to further evaluate mechanisms of action of this novel therapy. Four weeks after left anterior descending (LAD) artery ligation in pigs, the animals underwent re-thoracotomy with (shock-wave group, n = 6) or without (control group, n = 5) epicardial shock waves (300 impulses at 0.38 mJ/mm2 ) applied to the infarcted anterior wall. Efficacy endpoints were improvement of LVEF and induction of angiogenesis 6 weeks after shock-wave therapy. Safety endpoints were haemodynamic stability during treatment and myocardial damage. Four weeks after LAD ligation, LVEF decreased in both the shock-wave (43 ± 3%, p heart failure exerted a positive effect on LVEF improvement and did not show any adverse effects. Angiogenesis was induced by stimulation of VEGF receptors. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.
Trauelsen, Anne Marie; Bendall, Sarah; Jansen, Jens E; Nielsen, Hanne-Grethe L; Pedersen, Marlene B; Trier, Christopher H; Haahr, Ulrik H; Simonsen, Erik
2016-08-01
The establishment of childhood adversities as risk factors for non-affective psychosis has derived a need to consider alternative interpretations of several psychosis-related factors. This paper sought to examine premorbid adjustment trajectories and social outcome factors in relation to childhood adversities. Perceived support has been found to decrease the risk of post-traumatic stress disorder, and we wished to compare perceived support in people with first-episode psychosis to non-clinical control persons and explore its relation to childhood adversities. Every individual presenting with a non-affective first-episode psychosis (F20-29, except F21) in Region Zealand over a 2-year period was approached for participation and the 101 consenting participants were matched to 101 people with no psychiatric disorders. Comprehensive demographic data were collected. Assessment instruments included the Premorbid Assessment Scale, the Global Assessment of Functioning scale and the Childhood Trauma Questionnaire. The latter represented the childhood adversities in addition to parental separation and institutionalization. There were no associations between number of childhood adversities and different social or academic premorbid trajectories. Those with more adversities had lower global functioning the year prior to treatment start and reported lower rates of perceived support during childhood along with less current face-to-face contact with family members. Lack of peer support remained a significant predictor of psychosis when adversities were adjusted for; peer support diminished the risk of psychosis caused by childhood adversities by 10%. Childhood adversities may not predict specific premorbid trajectories, but have an effect on global functioning when the psychosis has begun. Perceived support, especially from peers, may be important in the development of psychosis, and those with more adversities may represent a vulnerable subgroup who need more assistance to
Directory of Open Access Journals (Sweden)
Per Olsson
2007-06-01
Full Text Available In this article, we focus on adaptive governance of social-ecological systems (SES and, more specifically, on social factors that can enhance the fit between governance systems and ecosystems. The challenge lies in matching multilevel governance system, often characterized by fragmented organizational and institutional structures and compartmentalized and sectorized decision-making processes, with ecosystems characterized by complex interactions in time and space. The ability to create the right links, at the right time, around the right issues in multilevel governance systems is crucial for fostering responses that build social-ecological resilience and maintain the capacity of complex and dynamic ecosystems to generate services for human well-being. This is especially true in the face of uncertainty and during periods of abrupt change and reorganization. We draw on our earlier work in the Kristianstads Vattenrike Biosphere Reserve (KVBR, in southern Sweden, to provide new insights on factors that can improve such linking. We focus especially on the bridging function in SES and the factors that constrain bridging in multilevel governance systems, and strategies used to overcome these. We present two features that seem critical for linking organizations dynamically across multiple levels: 1 the role of bridging organizations and 2 the importance of leadership. Bridging organizations and the bridging function can be vulnerable to disturbance, but there are sources of resilience for securing these key structures and functions in SES. These include social mechanisms for combining multiple sources of knowledge, building moral and political support in social networks, and having legal and financial support as part of the adaptive governance structure.
Demirkaya, Nazli; Cohen, Sophie; Wit, Ferdinand W N M; Abramoff, Michael D; Schlingemann, Reinier O; Kuijpers, Taco W; Reiss, Peter; Pajkrt, Dasja; Verbraak, Frank D
2015-06-01
Subtle structural and functional neuroretinal changes have been described in human immunodeficiency virus (HIV)-infected adults without retinitis treated with combination antiretroviral therapy (cART). However, studies on this subject in HIV-infected children are scarce. This study aimed to assess the presence of (neuro)retinal functional and structural differences between a group of perinatally HIV-infected children on cART and age-, sex-, ethnicity-, and socioeconomically matched healthy controls. All participants underwent an extensive ophthalmological examination, including functional tests as well as optical coherence tomography, to measure individual retinal layer thicknesses. Multivariable mixed linear regression models were used to assess possible associations between HIV status (and other HIV-related parameters) and ocular parameters, while accounting for the inclusion of both eyes and several known confounders. Thirty-three HIV-infected children (median age 13.7 years [interquartile range (IQR), 12.2-15.8], median CD4+ T-cell count 760 cells/mm3, 82% with an undetectable HIV viral load [VL]), and 36 controls (median age 12.1 years [IQR, 11.5-15.8]) were included. Contrast sensitivity (CS) was significantly lower in the HIV-infected group (1.74 vs. 1.76 logCS; P = 0.006). The patients had a significantly thinner foveal thickness (-11.2 μm, P = 0.012), which was associated with a higher peak HIV VL (-10.3 μm per log copy/mL, P = 0.016). In this study, we found a decrease in foveal thickness in HIV-infected children, which was associated with a higher peak VL. Longitudinal studies are warranted to confirm our findings and to determine the course and clinical consequences of these foveal changes.
Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets
Miceli, Giacomo; Pasquarello, Alfredo
2016-01-01
We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, the electronic structure and the atomic forces are self-consistently determined within the same theoretical scheme based on a nonlocal density functional accounting for van der Waals interactions. The overall properties of liquid water achieved within the two frameworks are in excellent agreement with each other. Thus, our study supports that implementations with plane-wave or atomic-orbital basis sets yield equivalent results and can be used indiscriminately in study of liquid water or aqueous solutions.
Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets.
Miceli, Giacomo; Hutter, Jürg; Pasquarello, Alfredo
2016-08-09
We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, the electronic structure and the atomic forces are self-consistently determined within the same theoretical scheme based on a nonlocal density functional accounting for van der Waals interactions. The overall properties of liquid water achieved within the two frameworks are in excellent agreement with each other. Thus, our study supports that implementations with plane-wave or atomic-orbital basis sets yield equivalent results and can be used indiscriminately in study of liquid water or aqueous solutions.
Lapierre, David; Kochanov, Roman; Kokoouline, Viatcheslav; Tyuterev, Vladimir
2016-01-01
Energies and lifetimes (widths) of vibrational states above the lowest dissociation limit of $^{16}$O$_3$ were determined using a previously-developed efficient approach, which combines hyperspherical coordinates and a complex absorbing potential. The calculations are based on a recently-computed potential energy surface of ozone determined with a spectroscopic accuracy [J. Chem. Phys. {\\bf 139}, 134307 (2013)]. The effect of permutational symmetry on rovibrational dynamics and the density of resonance states in O$_3$ is discussed in detail. Correspondence between quantum numbers appropriate for short- and long-range parts of wave functions of the rovibrational continuum is established. It is shown, by symmetry arguments, that the allowed purely vibrational ($J=0$) levels of $^{16}$O$_3$ and $^{18}$O$_3$, both made of bosons with zero nuclear spin, cannot dissociate on the ground state potential energy surface. Energies and wave functions of bound states of the ozone isotopologue $^{16}$O$_3$ with rotational ...
Kirichuk, V F; Maĭborodin, A V; Volin, M V; Krenitskiĭ, A P; Tupikin, V D
2001-01-01
A comparative analysis was made of the effect of two kinds of EMI MMD-radiation: EMI MMD-waves, generated by a vehicle "Jav-1 M" (42.2 and 53.5 HHz), and EMI MMD-waves exerting influence with frequencies of molecular spectrum of radiation and nitric oxide absorption (150.176-150.644 HHz), obtained with a specially created generator, with respect to their influence on the functional ability of platelets of unstable angina pectoris patients. It was shown that in vitro EMI MMD-fluctuations with frequencies of molecular spectrum of radiation and nitric oxide absorption exert a stronger inhibiting influence on the functional activity of platelets of unstable angina pectoris patients. Features of the action of various kinds of EMI MMD-effect on the activative-high-speed characteristics of platelet aggregation are shown.
Crilly, Mike; Coch, Christoph; Bruce, Margaret; Clark, Hazel; Williams, David
2007-01-01
Abstract Pulse wave analysis (PWA) using applanation tonometry is a non-invasive technique for assessing cardiovascular function. It produces three important indices: ejection duration index (ED%), augmentation index adjusted for heart rate (AIX@75), and subendocardial viability ratio (SEVR%). The aim of this study was to assess within- and between-observer repeatability of these measurements. After resting supine for 15 minutes, 20 ambulant patients (16 male) in sinus rhythm under...
Min, Byeong June; Shin, Won Chul; Park, Jae Ik
2016-01-01
We studied the structural and the electronic properties of ionized and neutral small Au clusters via plane wave pseudopotential calculations. All except the anionic heptamer favor one-dimensional zigzag structures or two-dimensional arrangements of triangles. The HOMO-LUMO (highest occupied molecular orbital - lowest unoccupied molecular orbital) gap, the ionization energy, and the electronic affinity exhibit even-odd variation as a function of the cluster size.
Asiri, Sharefa M.
2017-10-19
In this paper, a method based on modulating functions is proposed to estimate the Cerebral Blood Flow (CBF). The problem is written in an input estimation problem for a damped wave equation which is used to model the spatiotemporal variations of blood mass density. The method is described and its performance is assessed through some numerical simulations. The robustness of the method in presence of noise is also studied.
Directory of Open Access Journals (Sweden)
Seham Ragab
2015-08-01
Full Text Available Background: Cardiac iron toxicity is the leading cause of death among β-halassaemia major (TM patients. Once heart failure becomes overt , it will be difficult to reverse . Objectives: To investigate non overt cardiac dysfunctions in TM patients using pulsed wave Tissue Doppler Imaging (TD I and its relation to the iron overload and brain natruritic peptide (BNP. Methods: Thorough clinical , conventional echo and pulsed wave TDI parameters were compared between asymtomatic 25 β-TM patients and 20 age and gender matched individuals. Serum ferritin and plasma BNP levels were assayed by ELISA . Results: TM patients had significant higher mitral inflow early diastolic (E wave and non significant other conventional echo parameters. Pulsed wave TDI revealed systolic and diastolic dysfunctions in the form of significant higher isovolumetric contraction time (ICT , ejection time ( E T and isovolumetric relaxation time (IRT with significantly lower mitral annulus early diastolic velocity E` (12.07 ±2.06 vs 15.04±2.65 ,P= 0.003 in patients compared to controls. Plasma BNP was higher in patients compared to the controls. Plasma BNP and serum ferritin had significant correlation with each other and with pulsed wave conventional and TDI indices of systolic and diastolic functions. Patients with E/E` ≥ 8 had significant higher serum ferritin and plasma BNP levels compared to those with E/E` ratio < 8 without difference in Hb levels .Conclusion: Pulsed wave TDI is an important diagnostic tool for latent cardiac dysfunction in iron loaded TM patients and is related to iron overload and BNP .
Energy Technology Data Exchange (ETDEWEB)
Puri, Nidhi; Manoharlal, Raman; Sharma, Monika [Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India); Sanglard, Dominique [Institut de Microbiologie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne (Switzerland); Prasad, Rajendra, E-mail: rp47jnu@gmail.com [Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)
2011-01-07
Research highlights: {yields} First report to demonstrate an in vivo expression system of an ABC multidrug transporter CgCdr1p of C. glabrata. {yields} First report on the structure and functional characterization of CgCdr1p. {yields} Functional conservation of divergent but typical residues of CgCdr1p. {yields} CgCdr1p elicits promiscuity towards substrates and has a large drug binding pocket with overlapping specificities. -- Abstract: We have taken advantage of the natural milieu of matched pair of azole sensitive (AS) and azole resistant (AR) clinical isolates of Candida glabrata for expressing its major ABC multidrug transporter, CgCdr1p for structure and functional analysis. This was accomplished by tagging a green fluorescent protein (GFP) downstream of ORF of CgCDR1 and integrating the resultant fusion protein at its native chromosomal locus in AS and AR backgrounds. The characterization confirmed that in comparison to AS isolate, CgCdr1p-GFP was over-expressed in AR isolates due to its hyperactive native promoter and the GFP tag did not affect its functionality in either construct. We observed that in addition to Rhodamine 6 G (R6G) and Fluconazole (FLC), a recently identified fluorescent substrate of multidrug transporters Nile Red (NR) could also be expelled by CgCdr1p. Competition assays with these substrates revealed the presence of overlapping multiple drug binding sites in CgCdr1p. Point mutations employing site directed mutagenesis confirmed that the role played by unique amino acid residues critical to ATP catalysis and localization of ABC drug transporter proteins are well conserved in C. glabrata as in other yeasts. This study demonstrates a first in vivo novel system where over-expression of GFP tagged MDR transporter protein can be driven by its own hyperactive promoter of AR isolates. Taken together, this in vivo system can be exploited for the structure and functional analysis of CgCdr1p and similar proteins wherein the arte-factual concerns
Evans functions and bifurcations of nonlinear waves of some nonlinear reaction diffusion equations
Zhang, Linghai
2017-10-01
The main purposes of this paper are to accomplish the existence, stability, instability and bifurcation of the nonlinear waves of the nonlinear system of reaction diffusion equations ut =uxx + α [ βH (u - θ) - u ] - w, wt = ε (u - γw) and to establish the existence, stability, instability and bifurcation of the nonlinear waves of the nonlinear scalar reaction diffusion equation ut =uxx + α [ βH (u - θ) - u ], under different conditions on the model constants. To establish the bifurcation for the system, we will study the existence and instability of a standing pulse solution if 0 1; the existence and instability of two standing wave fronts if 2 (1 + αγ) θ = αβγ and 0 0 is a positive constant, if 0 mathematical neuroscience.
Minozzi, M; Bonora, S; Sergienko, A V; Vallone, G; Villoresi, P
2013-02-15
We present an efficient method for optimizing the spatial profile of entangled-photon wave function produced in a spontaneous parametric down conversion process. A deformable mirror that modifies a wavefront of a 404 nm CW diode laser pump interacting with a nonlinear β-barium borate type-I crystal effectively controls the profile of the joint biphoton function. The use of a feedback signal extracted from the biphoton coincidence rate is used to achieve the optimal wavefront shape. The optimization of the two-photon coupling into two, single spatial modes for correlated detection is used for a practical demonstration of this physical principle.
DEFF Research Database (Denmark)
Feidenhans'l, Nikolaj Agentoft; Jensen, Thomas Glasdam; Lafleur, Josiane P.
2013-01-01
We demonstrate the use of functional surface groups inherently present on off-stoichiometric thiol−ene polymers, for site-specific immobilization of biomolecules and detection by evanescent wave-induced fluorescence. An optofluidic chip featuring an embedded thiol−ene waveguide was selectively...... functionalized with biotin using photografting. The biotin was used for immobilization of fluorescently labelled streptavidin, and experiments revealed a linear correlation between streptavidin concentration and fluorescent intensity. To further demonstrate the attractiveness of using thiol−ene for optofluidic...... devices, the optical properties of thiol−ene was evaluated by determining the transparency and refractive index of the cured polymer....
DEFF Research Database (Denmark)
Feidenhans, Nikolaj A.; Jensen, Thomas Glasdam; Lafleur, Josiane P.
2013-01-01
We demonstrate the use of functional surface groups inherently present on off-stoichiometric thiol-ene polymers, for site-specific immobilization of biomolecules and detection by evanescent wave-induced fluorescence. An optofluidic chip featuring an embedded thiol-ene waveguide was selectively...... functionalized with biotin using photografting. The biotin was used for immobilization of fluorescently labelled streptavidin, and experiments revealed a linear correlation between streptavidin concentration and fluorescent intensity. To further demonstrate the attractiveness of using thiol-ene for optofluidic...... devices, the optical properties of thiol-ene was evaluated by determining the transparency and refractive index of the cured polymer....
Dadashi, Mohsen; Birashk, Behrooz; Taremian, Farhad; Asgarnejad, Ali Asghar; Momtazi, Saeed
2015-01-01
The basic objective of this study is to investigate the effects of alpha and theta brain waves amplitude increase in occipital area on reducing the severity of symptoms of generalized anxiety disorder and to increase the global functioning level in patients with GAD. This study is a quasi-experimental study with pre-test and post-test with two groups. For this purpose, 28 patients who had been referred to Sohrawardi psychiatric and clinical psychology center in Zanjan were studied based on the interview with the psychiatrist, clinical psychologist and using clinical diagnostic criteria for the Diagnostic and Statistical Manual of Mental Disorders text revision - the DSM-IV-TR Fourth Edition diagnosis of GAD, 14 subjects were studied in neurofeedback treatment group and 14 subjects in the waiting list group. Patients in both groups were evaluated at pre-test and post-test with General Anxiety Disorder Scale (GAD-7) and Global Assessment Functioning Scale (GAFs). The treatment group received fifteen 30-minute alpha training sessions and fifteen 30-minute theta brain training sessions in occipital area by neurofeedback training (treatment group). This evaluation was performed according to the treatment protocol to increase the alpha and theta waves. And no intervention was done in the waiting list group. But due to ethical issues after the completion of the study all the subjects in the waiting list group were treated. The results showed that increase of alpha and theta brain waves amplitude in occipital area in people with GAD can increase the global functioning level and can reduce symptoms of generalized anxiety disorder in a treatment group, but no such change was observed in the waiting list group. Increase of alpha and theta brain waves amplitude in occipital area can be useful in the treatment of people with GAD.
Deringer, Volker L; George, Janine; Dronskowski, Richard; Englert, Ulli
2017-05-16
Molecular compounds, organic and inorganic, crystallize in diverse and complex structures. They continue to inspire synthetic efforts and "crystal engineering", with implications ranging from fundamental questions to pharmaceutical research. The structural complexity of molecular solids is linked with diverse intermolecular interactions: hydrogen bonding with all its facets, halogen bonding, and other secondary bonding mechanisms of recent interest (and debate). Today, high-resolution diffraction experiments allow unprecedented insight into the structures of molecular crystals. Despite their usefulness, however, these experiments also face problems: hydrogen atoms are challenging to locate, and thermal effects may complicate matters. Moreover, even if the structure of a crystal is precisely known, this does not yet reveal the nature and strength of the intermolecular forces that hold it together. In this Account, we show that periodic plane-wave-based density functional theory (DFT) can be a useful, and sometimes unexpected, complement to molecular crystallography. Initially developed in the solid-state physics communities to treat inorganic solids, periodic DFT can be applied to molecular crystals just as well: theoretical structural optimizations "help out" by accurately localizing the elusive hydrogen atoms, reaching neutron-diffraction quality with much less expensive measurement equipment. In addition, phonon computations, again developed by physicists, can quantify the thermal motion of atoms and thus predict anisotropic displacement parameters and ORTEP ellipsoids "from scratch". But the synergy between experiment and theory goes much further than that. Once a structure has been accurately determined, computations give new and detailed insights into the aforementioned intermolecular interactions. For example, it has been debated whether short hydrogen bonds in solids have covalent character, and we have added a new twist to this discussion using an orbital
Chen, Ling; Wen, Lianxing; Zheng, Tianyu
2005-11-01
The newly developed wave equation poststack depth migration method for receiver function imaging is applied to study the subsurface structures of the Japan subduction zone using the Fundamental Research on Earthquakes and Earth's Interior Anomalies (FREESIA) broadband data. Three profiles are chosen in the subsurface imaging, two in northeast (NE) Japan to study the subducting Pacific plate and one in southwest (SW) Japan to study the Philippine Sea plate. The descending Pacific plate in NE Japan is well imaged within a depth range of 50-150 km. The slab image exhibits a little more steeply dipping angle (˜32°) in the south than in the north (˜27°), although the general characteristics between the two profiles in NE Japan are similar. The imaged Philippine Sea plate in eastern SW Japan, in contrast, exhibits a much shallower subduction angle (˜19°) and is only identifiable at the uppermost depths of no more than 60 km. Synthetic tests indicate that the top 150 km of the migrated images of the Pacific plate is well resolved by our seismic data, but the resolution of deep part of the slab images becomes poor due to the limited data coverage. Synthetic tests also suggest that the breakdown of the Philippine Sea plate at shallow depths reflects the real structural features of the subduction zone, rather than caused by insufficient coverage of data. Comparative studies on both synthetics and real data images show the possibility of retrieval of fine-scale structures from high-frequency contributions if high-frequency noise can be effectively suppressed and a small bin size can be used in future studies. The derived slab geometry and image feature also appear to have relatively weak dependence on overlying velocity structure. The observed seismicity in the region confirms the geometries inferred from the migrated images for both subducting plates. Moreover, the deep extent of the Pacific plate image and the shallow breakdown of the Philippine Sea plate image are
Mohammad Mirzaei Zarandi, Soroush
2014-01-01
The aim of this research is to develop and build a low cost portable integrated frequency-domain and continuous wave (CW) system for real-time spectroscopic imaging of human tissue. This system measures four tissue chromophore concentrations (water, lipid, deoxygenated, and oxygenated hemoglobin) using eight near-infrared wavelengths ranging from 660nm to 980nm, in real-time. The frequency domain (FD) module measures the phase and amplitude of photon density waves from 50-500 MHz with an oper...
Compton upconversion of twisted photons: backscattering of particles with non-planar wave functions
Jentschura, U. D.; Serbo, V. G.
2011-03-01
Twisted photons are not plane waves, but superpositions of plane waves with a defined projection ℏm of the orbital angular momentum onto the propagation axis ( m is integer and may attain values m≫1). Here, we describe in detail the possibility to produce high-energy twisted photons by backward Compton scattering of twisted laser photons on ultra-relativistic electrons with a Lorentz-factor γ= E/( m e c 2)≫1. When a twisted laser photon with the energy ℏω˜1 eV performs a collision with an electron and scatters backward, the final twisted photon conserves the angular momentum m, but its energy ℏω' is increased considerably: ω'/ ω=4 γ 2/(1+ x), where x=4 Eℏω/( m e c 2)2. The S matrix formalism for the description of scattering processes is particularly simple for plane waves with definite 4-momenta. However, in the considered case, this formalism must be enhanced because the quantum state of twisted particles cannot be reduced to plane waves. This implies that the usual notion of a cross section is inapplicable, and we introduce and calculate an averaged cross section for a quantitative description of the process. The energetic upconversion of twisted photons may be of interest for experiments with the excitation and disintegration of atoms and nuclei, and for studying the photo-effect and pair production off nuclei in previously unexplored regimes.
Calculating the fine structure of a Fabry-Perot resonator using spheroidal wave functions
Zeppenfeld, M.; Pinkse, Pepijn Willemszoon Harry
2010-01-01
A new set of vector solutions to Maxwell’s equations based on solutions to the wave equation in spheroidal coordinates allows laser beams to be described beyond the paraxial approximation. Using these solutions allows us to calculate the complete first-order corrections in the short-wavelength limit
2010-09-01
1274-1298. —. .and I. R Young. 21X13: Revisiting the Pierson-Moskowit7 asymptotic limits for fully developed wind waves. J. / VIVA Oce- anogr...stale of the art . Prog. Oceanogr., 75,603-674, doi:10.1016/j.pocean.2007.05.005 Wu, C. H.. and H. M. Nepf. 2002: Breaking criteria and energy losses
Tan, Shurun
The objective of my research is two-fold: to study wave scattering phenomena in dense volumetric random media and in periodic wave functional materials. For the first part, the goal is to use the microwave remote sensing technique to monitor water resources and global climate change. Towards this goal, I study the microwave scattering behavior of snow and ice sheet. For snowpack scattering, I have extended the traditional dense media radiative transfer (DMRT) approach to include cyclical corrections that give rise to backscattering enhancements, enabling the theory to model combined active and passive observations of snowpack using the same set of physical parameters. Besides DMRT, a fully coherent approach is also developed by solving Maxwell's equations directly over the entire snowpack including a bottom half space. This revolutionary new approach produces consistent scattering and emission results, and demonstrates backscattering enhancements and coherent layer effects. The birefringence in anisotropic snow layers is also analyzed by numerically solving Maxwell's equation directly. The effects of rapid density fluctuations in polar ice sheet emission in the 0.5˜2.0 GHz spectrum are examined using both fully coherent and partially coherent layered media emission theories that agree with each other and distinct from incoherent approaches. For the second part, the goal is to develop integral equation based methods to solve wave scattering in periodic structures such as photonic crystals and metamaterials that can be used for broadband simulations. Set upon the concept of modal expansion of the periodic Green's function, we have developed the method of broadband Green's function with low wavenumber extraction (BBGFL), where a low wavenumber component is extracted and results a non-singular and fast-converging remaining part with simple wavenumber dependence. We've applied the technique to simulate band diagrams and modal solutions of periodic structures, and to
Energy Technology Data Exchange (ETDEWEB)
Yunta Carretero; Rodriguez Mayquez, E.
1974-07-01
In this paper is described the objective, basis, carrying out in FORTRAN language and use of the program ORBITALES. This program calculate atomic wave function in the case of ths analytical central potential (Author) 8 refs.
Fang, Honghua; Balazs, Daniel M.; Protesescu, Loredana; Kovalenko, Maksym V.; Loi, Maria Antonietta
2015-01-01
Colloidal semiconductor quantum dots (QDs) are extraordinarily appealing for the development of cheap and large area solar cells due to high absorption efficiency; tunable bandgap energies; and solution processability. Understanding:and controlling electronic wave function delocalitation in QD thin
Valor, A; Bonche, P
2000-01-01
We present in this paper the general framework of a method which permits to restore the rotational and particle number symmetries of wave functions obtained in Skyrme HF + BCS calculations. This restoration is nothing but a projection of mean-field intrinsic wave functions onto good particle number and good angular momentum. The method allows us also to mix projected wave functions. Such a configuration mixing is discussed for sets of HF + BCS intrinsic states generated in constrained calculations with suitable collective variables. This procedure gives collective states which are eigenstates of the particle number and the angular momentum operators and between which transition probabilities are calculated. An application to sup 2 sup 4 Mg is presented, with mean-field wave functions generated by axial quadrupole constraints. Theoretical spectra and transition probabilities are compared to the experiment.
Wave function modelling of a pendulum-spring system exhibiting simple harmonic motion
Ostrander, John
2016-01-01
Instructors are always looking for ideas and methods to deliver lessons and it’s sometimes difficult to pass along abstract concepts to students. Here, we have developed an ‘all in one’ summary of wave mechanics from start to finish then connected to solving for the wave equation. The connections between underlying concepts are assembled here such that laboratory exercises flow from one concept to the next, while leaving opportunity for review and re-teaching supporting topics. Using no special equipment, which is particularly useful for public schools, and technology that is widely available and often free to use, makes this approach especially attractive. The employment of mathematical transforms adds more here than a typical pendulum lab would contain while using most of the equations found in a typical physics textbook that apply to SHM, while simultaneously revisiting and reviewing previous concepts.
Ball, J. S.; Sheehan, A. F.; Stachnik, J. C.; Lin, F.; Collins, J. A.
2013-12-01
We have developed a joint Monte Carlo inversion of teleseismic receiver functions, seafloor compliance, and Rayleigh wave dispersion and apply it here to ocean bottom seismic (OBS) data from offshore New Zealand. With this method we estimate sediment and crustal thickness and shear velocity structure beneath the Bounty Trough and the Tasman Sea flanking the South Island of New Zealand. Teleseismic receiver functions and surface wave dispersion measurements provide complementary constraints on shear velocity structure and interface depths beneath seismic stations. At ocean bottom seismic (OBS) stations the interpretation of these measurements is complicated by strong sediment reverberations that obscure deeper impedance contrasts such as the Moho. In principle, the seafloor's response to ocean loading from infragravity waves (seafloor compliance) can be used to determine shallow shear velocity information. This velocity information can subsequently be used to better model the receiver function reverberations, allowing deeper interfaces of tectonic interest to be resolved. Data for this study were acquired in 2009-2010 by the Marine Observations of Anisotropy Near Aotearoa (MOANA) experiment, which deployed 30 broadband OBS and differential pressure gauges (DPGs) off the South Island of New Zealand. High-frequency (5Hz) receiver functions were estimated using multitaper cross-correlation for events in a 30-90 degree epicentral distance range. Coherence-weighted stacks binned by epicentral distance were produced in the frequency domain to suppress noise. Seafloor compliance was measured using multitaper pressure and acceleration spectra averaged from 120 days of continuous data without large transient events. Seafloor compliance measurements on the order of 10-9 Pa-1 are sensitive to shear velocity structure in the uppermost 5km of the crust and sediments. Rayleigh dispersion measurements were obtained at periods of 6-27s from ambient noise cross correlation. Sediment
Directory of Open Access Journals (Sweden)
KATHERINE J. HOOT
2014-08-01
Full Text Available The purpose of this study was to evaluate the effectiveness of model, cover, copy, compare (MCCC, token system, and match to sample for teaching basic functional life skills with a middle age single student with disabilities. MCCC is a student-managed strategy that teaches discrete skills through errorless correction. Match to sample is another strategy that teaches how to identify and discriminate based on a visual representation of the identical information. The effectiveness of MCCC and match to sample was evaluated using a multiple baseline design. The results indicated that MCCC and match to sample was effective in teaching a single middle age school student with disabilities his name, phone number, home address, and emergency contact name and phone number. Maintenance of the basic functional life skills was also found; except for the emergency contact name. However, even if maintenance was not conducted on the final set, emergency phone number was maintained; this is attributed to the length of teaching sessions on the final set. The MCCC and match to sample interventions were both easy to implement and employ in the special education middle school classroom.
Martin, Alexandre; Torrent, Marc; Caracas, Razvan
2015-03-01
A formulation of the response of a system to strain and electric field perturbations in the pseudopotential-based density functional perturbation theory (DFPT) has been proposed by D.R Hamman and co-workers. It uses an elegant formalism based on the expression of DFT total energy in reduced coordinates, the key quantity being the metric tensor and its first and second derivatives. We propose to extend this formulation to the Projector Augmented-Wave approach (PAW). In this context, we express the full elastic tensor including the clamped-atom tensor, the atomic-relaxation contributions (internal stresses) and the response to electric field change (piezoelectric tensor and effective charges). With this we are able to compute the elastic tensor for all materials (metals and insulators) within a fully analytical formulation. The comparison with finite differences calculations on simple systems shows an excellent agreement. This formalism has been implemented in the plane-wave based DFT ABINIT code. We apply it to the computation of elastic properties and seismic-wave velocities of iron with impurity elements. By analogy with the materials contained in meteorites, tested impurities are light elements (H, O, C, S, Si).
Eikonal Approximation in AdS/CFT: Conformal Partial Waves and Finite N Four-Point Functions
Cornalba, L; Penedones, J; Schiappa, R; Cornalba, Lorenzo; Costa, Miguel S.; Penedones, Joao; Schiappa, Ricardo
2007-01-01
We introduce the impact-parameter representation for conformal field theory correlators of the form A ~ . This representation is appropriate in the eikonal kinematical regime, and approximates the conformal partial-wave decomposition in the limit of large spin and dimension of the exchanged primary. Using recent results on the two-point function _{shock} in the presence of a shock wave in Anti-de Sitter, and its relation to the discontinuity of the four-point amplitude A across a kinematical branch-cut, we find the high spin and dimension conformal partial- wave decomposition of all tree-level Anti-de Sitter Witten diagrams. We show that, as in flat space, the eikonal kinematical regime is dominated by the T-channel exchange of the massless particle with highest spin (graviton dominance). We also compute the anomalous dimensions of the high-spin O_1 O_2 composites. Finally, we conjecture a formula re-summing crossed-ladder Witten diagrams to all orders in the gravitational coupling.
Kwon, Myoungjin; Gang, Moonhee; Oh, Kyongok
2013-12-01
The purpose of the study was to examine the effect of group music therapy on brain waves, behavior, and cognitive function among patients with chronic schizophrenia. A quasi-experimental pretest-posttest design was used with nonequivalent control group. The potential participants were recruited from inpatients in a psychiatric facility in a metropolitan city, assigned either to the experimental group (n = 28) or to the control group (n = 27) according to their wards to avoid treatment contamination. The experimental group participated in the group music therapy for 13 sessions over 7 weeks while continuing their standard treatment. The control group only received a standard treatment provided in the hospitals. The outcome measures include brain wave by electroencephalography, behavior by Nurses' Observation Scale for Inpatient Evaluation, and cognitive function by Mini-Mental State Examination. After participating in 13 sessions of the group music therapy, alpha waves measured from eight different sites were consistently present for the experimental group (p = .006-.045) than the control group, revealing that the participants in the music therapy may have experienced more joyful emotions throughout the sessions. The experimental group also showed improved cognitive function (F = 13.46, p = .001) and positive behavior (social competence, social interest & personal neatness) while their negative behaviors was significantly less than those of the control group (F = 24.04, p group music therapy used in this study was an effective intervention for improving emotional relaxation, cognitive processing abilities along with positive behavioral changes in patients with chronic schizophrenia. Our results can be useful for establishing intervention strategies toward psychiatric rehabilitation for those who suffer from chronic mental illnesses. Copyright © 2013. Published by Elsevier B.V.
Yannouleas, Constantine; Landman, Uzi
2017-10-01
A constructive theoretical platform for the description of quantum space-time crystals uncovers for N interacting and ring-confined rotating particles the existence of low-lying states with proper space-time crystal behavior. The construction of the corresponding many-body trial wave functions proceeds first via symmetry breaking at the mean-field level followed by symmetry restoration using projection techniques. The ensuing correlated many-body wave functions are stationary states and preserve the rotational symmetries, and at the same time they reflect the point-group symmetries of the mean-field crystals. This behavior results in the emergence of sequences of select magic angular momenta Lm. For angular-momenta away from the magic values, the trial functions vanish. Symmetry breaking beyond the mean-field level can be induced by superpositions of such good-Lm many-body stationary states. We show that superposing a pair of adjacent magic angular momenta states leads to formation of special broken-symmetry states exhibiting quantum space-time-crystal behavior. In particular, the corresponding particle densities rotate around the ring, showing undamped and nondispersed periodic crystalline evolution in both space and time. The experimental synthesis of such quantum space-time-crystal wave packets is predicted to be favored in the vicinity of ground-state energy crossings of the Aharonov-Bohm-type spectra accessed via an externally applied, natural or synthetic, magnetic field. These results are illustrated here for Coulomb-repelling fermionic ions and for a lump of contact-interaction attracting bosons.
Lehtola, Susi; Tubman, Norm M.; Whaley, K. Birgitta; Head-Gordon, Martin
2017-10-01
Approximate full configuration interaction (FCI) calculations have recently become tractable for systems of unforeseen size, thanks to stochastic and adaptive approximations to the exponentially scaling FCI problem. The result of an FCI calculation is a weighted set of electronic configurations, which can also be expressed in terms of excitations from a reference configuration. The excitation amplitudes contain information on the complexity of the electronic wave function, but this information is contaminated by contributions from disconnected excitations, i.e., those excitations that are just products of independent lower-level excitations. The unwanted contributions can be removed via a cluster decomposition procedure, making it possible to examine the importance of connected excitations in complicated multireference molecules which are outside the reach of conventional algorithms. We present an implementation of the cluster decomposition analysis and apply it to both true FCI wave functions, as well as wave functions generated from the adaptive sampling CI algorithm. The cluster decomposition is useful for interpreting calculations in chemical studies, as a diagnostic for the convergence of various excitation manifolds, as well as as a guidepost for polynomially scaling electronic structure models. Applications are presented for (i) the double dissociation of water, (ii) the carbon dimer, (iii) the π space of polyacenes, and (iv) the chromium dimer. While the cluster amplitudes exhibit rapid decay with an increasing rank for the first three systems, even connected octuple excitations still appear important in Cr2, suggesting that spin-restricted single-reference coupled-cluster approaches may not be tractable for some problems in transition metal chemistry.
Grassi, Davide; Desideri, Giovambattista; Necozione, Stefano; Ruggieri, Fabrizio; Blumberg, Jeffrey B; Stornello, Michele; Ferri, Claudio
2012-09-01
Nitric oxide plays a pivotal role in regulating vascular tone. Different studies show endothelial function is impaired during hyperglycemia. Dark chocolate increases flow-mediated dilation in healthy and hypertensive subjects with and without glucose intolerance; however, the effect of pretreatment with dark chocolate on endothelial function and other vascular responses to hyperglycemia has not been examined. Therefore, we aimed to investigate the effects of flavanol-rich dark chocolate administration on (1) flow-mediated dilation and wave reflections; (2) blood pressure, endothelin-1 and oxidative stress, before and after oral glucose tolerance test (OGTT). Twelve healthy volunteers (5 males, 28.2±2.7 years) randomly received either 100 g/d dark chocolate or flavanol-free white chocolate for 3 days. After 7 days washout period, volunteers were switched to the other treatment. Flow-mediated dilation, stiffness index, reflection index, peak-to-peak time, blood pressure, endothelin-1 and 8-iso-PGF(2α) were evaluated after each treatment phase and OGTT. Compared with white chocolate, dark chocolate ingestion improved flow-mediated dilation (P=0.03), wave reflections, endothelin-1 and 8-iso-PGF(2α) (Pflavanol-rich dark chocolate. These results suggest cocoa flavanols may contribute to vascular health by reducing the postprandial impairment of arterial function associated with the pathogenesis of atherosclerosis.
Pannert, W.; Ring, P.; Gambhir, Y. K.
1985-09-01
Angular-momentum- and number-projected Hartree-Fock-Bogoliubov (HFB) wave functions of translational and deformed rare earth nuclei are analyzed in terms of fermion pairs coupled to angular momenta L = 0 (S), 2 (D), 4 (G),/3. The fermion space is truncated to contain only S-D or S-D-G pairs. The variation is carried out before and after angular momentum projection and also with different truncations. The influence of the truncation on physical quantities such as moments of inertia, quadrupole moments or pair transfer matrix elements is discussed.
... for Kids ▸ Stinging Insect Matching Game Share | Stinging Insect Matching Game Stinging insects can ruin summer fun for those who are ... the difference between the different kinds of stinging insects in order to keep your summer safe and ...
Directory of Open Access Journals (Sweden)
Lee HY
2015-10-01
using the drug.Results: Of the 587 patients enrolled in the study, 257 took tiotropium. Following propensity score matching, 404 patients were included in the analysis. The mean annual rate of post-BD FEV1 decline was 23.9 (tiotropium and 22.5 (control mL/yr (P=0.86; corresponding pre-BD values were 30.4 and 21.9 mL/yr (P=0.31, respectively. Mean annual rate of post-BD FVC decline was 55.1 (tiotropium and 43.5 (control mL/yr (P=0.33; corresponding pre-BD values were 37.1 and 33.3 mL/yr (P=0.13.Conclusion: Therefore, tiotropium does not reduce the rate of lung function decline in COPD patients with FEV1≥70%. Keywords: tiotropium, chronic obstructive pulmonary disease, lung function decline
A functional integral approach to shock wave solutions of Euler equations with spherical symmetry
Yang, Tong
1995-08-01
For n×n systems of conservation laws in one dimension without source terms, the existence of global weak solutions was proved by Glimm [1]. Glimm constructed approximate solutions using a difference scheme by solving a class of Riemann problems. In this paper, we consider the Cauchy problem for the Euler equations in the spherically symmetric case when the initial data are small perturbations of the trivial solution, i.e., u≡0 and ρ≡ constant, where u is velocity and ρ is density. We show that this Cauchy problem can be reduced to an ideal nonlinear problem approximately. If we assume all the waves move at constant speeds in the ideal problem, by using Glimm's scheme and an integral approach to sum the contributions of the reflected waves that correspond to each path through the solution, we get uniform bounds on the L ∞ norm and total variational norm of the solutions for all time. The geometric effects of spherical symmetry leads to a non-integrable source term in the Euler equations. Correspondingly, we consider an infinite reflection problem and solve it by considering the cancellations between reflections of different orders in our ideal problem. Thus we view this as an analysis of the interaction effects at the quadratic level in a nonlinear model problem for the Euler equations. Although it is far more difficult to obtain estimates in the exact solutions of the Euler equations due to the problem of controlling the time at which the cancellations occur, we believe that this analysis of the wave behaviour will be the first step in solving the problem of existence of global weak solutions for the spherically symmetric Euler equations outside of fixed ball.
Beecham, Jonathan; Bruggeman, Jorn; Aldridge, John; Mackinson, Steven
2016-03-01
End-to-end modelling is a rapidly developing strategy for modelling in marine systems science and management. However, problems remain in the area of data matching and sub-model compatibility. A mechanism and novel interfacing system (Couplerlib) is presented whereby a physical-biogeochemical model (General Ocean Turbulence Model-European Regional Seas Ecosystem Model, GOTM-ERSEM) that predicts dynamics of the lower trophic level (LTL) organisms in marine ecosystems is coupled to a dynamic ecosystem model (Ecosim), which predicts food-web interactions among higher trophic level (HTL) organisms. Coupling is achieved by means of a bespoke interface, which handles the system incompatibilities between the models and a more generic Couplerlib library, which uses metadata descriptions in extensible mark-up language (XML) to marshal data between groups, paying attention to functional group mappings and compatibility of units between models. In addition, within Couplerlib, models can be coupled across networks by means of socket mechanisms. As a demonstration of this approach, a food-web model (Ecopath with Ecosim, EwE) and a physical-biogeochemical model (GOTM-ERSEM) representing the North Sea ecosystem were joined with Couplerlib. The output from GOTM-ERSEM varies between years, depending on oceanographic and meteorological conditions. Although inter-annual variability was clearly present, there was always the tendency for an annual cycle consisting of a peak of diatoms in spring, followed by (less nutritious) flagellates and dinoflagellates through the summer, resulting in an early summer peak in the mesozooplankton biomass. Pelagic productivity, predicted by the LTL model, was highly seasonal with little winter food for the higher trophic levels. The Ecosim model was originally based on the assumption of constant annual inputs of energy and, consequently, when coupled, pelagic species suffered population losses over the winter months. By contrast, benthic populations
Matching critical intersection hypergraphs
DEFF Research Database (Denmark)
Henning, Michael A.; Yeo, Anders
2014-01-01
A matching in a hypergraph H is a set of pairwise vertex disjoint edges in H and the matching number of H is the maximum cardinality of a matching in H. A hypergraph H is an intersecting hypergraph if every two distinct edges of H have a non-empty intersection. Equivalently, H is an intersecting...
-Advanced Models for Tsunami and Rogue Waves
Directory of Open Access Journals (Sweden)
D. W. Pravica
2012-01-01
Full Text Available A wavelet , that satisfies the q-advanced differential equation for , is used to model N-wave oscillations observed in tsunamis. Although q-advanced ODEs may seem nonphysical, we present an application that model tsunamis, in particular the Japanese tsunami of March 11, 2011, by utilizing a one-dimensional wave equation that is forced by . The profile is similar to tsunami models in present use. The function is a wavelet that satisfies a q-advanced harmonic oscillator equation. It is also shown that another wavelet, , matches a rogue-wave profile. This is explained in terms of a resonance wherein two small amplitude forcing waves eventually lead to a large amplitude rogue. Since wavelets are used in the detection of tsunamis and rogues, the signal-analysis performance of and is examined on actual data.
Robinson, Paul J.; Pineda Flores, Sergio D.; Neuscamman, Eric
2017-10-01
In the regime where traditional approaches to electronic structure cannot afford to achieve accurate energy differences via exhaustive wave function flexibility, rigorous approaches to balancing different states' accuracies become desirable. As a direct measure of a wave function's accuracy, the energy variance offers one route to achieving such a balance. Here, we develop and test a variance matching approach for predicting excitation energies within the context of variational Monte Carlo and selective configuration interaction. In a series of tests on small but difficult molecules, we demonstrate that the approach is effective at delivering accurate excitation energies when the wave function is far from the exhaustive flexibility limit. Results in C3, where we combine this approach with variational Monte Carlo orbital optimization, are especially encouraging.
Electromagnetic ultrasonic guided waves
Huang, Songling; Li, Weibin; Wang, Qing
2016-01-01
This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.
Zhang, Zhendong
2016-07-26
We present a surface-wave inversion method that inverts for the S-wave velocity from the Rayleigh wave dispersion curve using a difference approximation to the gradient of the misfit function. We call this wave equation inversion of skeletonized surface waves because the skeletonized dispersion curve for the fundamental-mode Rayleigh wave is inverted using finite-difference solutions to the multi-dimensional elastic wave equation. The best match between the predicted and observed dispersion curves provides the optimal S-wave velocity model. Our method can invert for lateral velocity variations and also can mitigate the local minimum problem in full waveform inversion with a reasonable computation cost for simple models. Results with synthetic and field data illustrate the benefits and limitations of this method. © 2016 Elsevier B.V.
Energy Technology Data Exchange (ETDEWEB)
Vieira, H.S., E-mail: horacio.santana.vieira@hotmail.com [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil); Centro de Ciências, Tecnologia e Saúde, Universidade Estadual da Paraíba, CEP 58233-000, Araruna, PB (Brazil); Bezerra, V.B., E-mail: valdir@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)
2016-10-15
We apply the confluent Heun functions to study the resonant frequencies (quasispectrum), the Hawking radiation and the scattering process of scalar waves, in a class of spacetimes, namely, the ones generated by a Kerr–Newman–Kasuya spacetime (dyon black hole) and a Reissner–Nordström black hole surrounded by a magnetic field (Ernst spacetime). In both spacetimes, the solutions for the angular and radial parts of the corresponding Klein–Gordon equations are obtained exactly, for massive and massless fields, respectively. The special cases of Kerr and Schwarzschild black holes are analyzed and the solutions obtained, as well as in the case of a Schwarzschild black hole surrounded by a magnetic field. In all these special situations, the resonant frequencies, Hawking radiation and scattering are studied. - Highlights: • Charged massive scalar field in the dyon black hole and massless scalar field in the Ernst spacetime are analyzed. • The confluent Heun functions are applied to obtain the solution of the Klein–Gordon equation. • The resonant frequencies are obtained. • The Hawking radiation and the scattering process of scalar waves are examined.
Wave Equation Inversion of Skeletonized SurfaceWaves
Zhang, Zhendong
2015-08-19
We present a surface-wave inversion method that inverts for the S-wave velocity from the Rayleigh dispersion curve for the fundamental-mode. We call this wave equation inversion of skeletonized surface waves because the dispersion curve for the fundamental-mode Rayleigh wave is inverted using finite-difference solutions to the wave equation. The best match between the predicted and observed dispersion curves provides the optimal S-wave velocity model. Results with synthetic and field data illustrate the benefits and limitations of this method.
Directory of Open Access Journals (Sweden)
A. J. Perez-Diaz
2010-08-01
Full Text Available Fingerprint verification is the most important step in the fingerprint-based biometric systems. The matching score islinked to the chance of identifying a person. Nowadays, two fingerprint matching methods are the most popular: thecorrelation-based method and the minutiae-based method. In this work, three biometric systems were evaluated:Neurotechnology Verifinger 6.0 Extended, Innovatrics IDKit SDK and Griaule Fingerprint SDK 2007. The evaluationwas performed according to the experiments of the Fingerprint Verification Competition (FVC. The influence of thefingerprint rotation degrees on false match rate (FMR and false non-match rate (FNMR was evaluated. The resultsshowed that the FMR values increase as rotation degrees increase too, meanwhile, the FNMR values decrease.Experimental results demonstrate that Verifinger SDK shows good performance on false non-match testing, with anFNMR mean of 7%, followed by IDKit SDK (6.71% ~ 13.66% and Fingerprint SDK (50%. However, Fingerprint SDKdemonstrates a better performance on false match testing, with an FMR mean of ~0%, followed by Verifinger SDK(7.62% - 9% and IDKit SDK (above 28%. As result of the experiments, Verifinger SDK had, in general, the bestperformance. Subsequently, we calculated the regression functions to predict the behavior of FNMR and FMR fordifferent threshold values with different rotation degrees.
Bubin, Sergiy; Stanke, Monika; Adamowicz, Ludwik
2017-06-01
In our previous work S. Bubin et al., Chem. Phys. Lett. 647, 122 (2016), 10.1016/j.cplett.2016.01.056, it was established that complex explicitly correlated one-center all-particle Gaussian functions (CECGs) provide effective basis functions for very accurate nonrelativistic molecular non-Born-Oppenheimer calculations. In this work, we advance the molecular CECGs approach further by deriving and implementing algorithms for calculating the leading relativistic corrections within this approach. The algorithms are tested in the calculations of the corrections for all 23 bound pure vibrational states of the HD+ ion.
On Green's function for 3-D wave-body interaction in a channel
DEFF Research Database (Denmark)
Xia, Jinzhu
1997-01-01
An analytical and numerical study is presented for efficient evaluation of the Green's function that satisfies the linear free surface condition and the non-penetration condition on the channel bottomand the side walls. the formulation is based on the open-sea green's function and the complete...
Naoto Miura; Takashi Watanabe
2016-01-01
Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between...
Andreev, Pavel A.; Kuz'menkov, L. S.
2017-11-01
A consideration of waves propagating parallel to the external magnetic field is presented. The dielectric permeability tensor is derived from the quantum kinetic equations with non-trivial equilibrium spin-distribution functions in the linear approximation on the amplitude of wave perturbations. It is possible to consider the equilibrium spin-distribution functions with nonzero z-projection proportional to the difference of the Fermi steps of electrons with the chosen spin direction, while x- and y-projections are equal to zero. It is called the trivial equilibrium spin-distribution functions. In the general case, x- and y-projections of the spin-distribution functions are nonzero which is called the non-trivial regime. A corresponding equilibrium solution is found in Andreev [Phys. Plasmas 23, 062103 (2016)]. The contribution of the nontrivial part of the spin-distribution function appears in the dielectric permeability tensor in the additive form. It is explicitly found here. A corresponding modification in the dispersion equation for the transverse waves is derived. The contribution of the nontrivial part of the spin-distribution function in the spectrum of transverse waves is calculated numerically. It is found that the term caused by the nontrivial part of the spin-distribution function can be comparable with the classic terms for the relatively small wave vectors and frequencies above the cyclotron frequency. In a majority of regimes, the extra spin caused term dominates over the spin term found earlier, except the small frequency regime, where their contributions in the whistler spectrum are comparable. A decrease of the left-hand circularly polarized wave frequency, an increase of the high-frequency right-hand circularly polarized wave frequency, and a decrease of frequency changing by an increase of frequency at the growth of the wave vector for the whistler are found. A considerable decrease of the spin wave frequency is found either. It results in an
Shega, Joseph W; Sunkara, Priya D; Kotwal, Ashwin; Kern, David W; Henning, Sara L; McClintock, Martha K; Schumm, Philip; Waite, Linda J; Dale, William
2014-11-01
To describe the development of a multidimensional test of cognition for the National Social life, Health and Aging Project (NSHAP), the Chicago Cognitive Function Measure (CCFM). CCFM development included 3 steps: (a) A pilot test of the Montreal Cognitive Assessment (MoCA) to create a standard protocol, choose specific items, reorder items, and improve clarity; (b) integration into a CAPI-based format; and (c) evaluation of the performance of the CCFM in the field. The CCFM was subsequently incorporated into NSHAP, Wave 2 (n = 3,377). The pre-test (n = 120) mean age was 71.35 (SD 8.40); 53% were female, 69% white, and 70% with college or greater education. The MoCA took an average of 15.6min; the time for the CCFM was 12.0 min. CCFM scores (0-20) can be used as a continuous outcome or to adjust for cognition in a multivariable analysis. CCFM scores were highly correlated with MoCA scores (r = .973). Modeling projects MoCA scores from CCFM scores using the equation: MoCA = (1.14 × CCFM) + 6.83. In Wave 2, the overall weighted mean CCFM score was 13.9 (SE 0.13). A survey-based adaptation of the MoCA was successfully integrated into a nationally representative sample of older adults, NSHAP Wave 2. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Koju, Vijay; Robertson, William M
2017-06-12
Dielectric multilayer structures with a grating profile on the top-most layer adds an additional degree of freedom to the phase matching conditions for Bloch surface wave excitation. The conditions for Bloch surface wave coupling can be achieved by rotating both polar and azimuthal angles. The generation of Bloch surface waves as a function of azimuthal angle has similar characteristics to conventional grating coupled Bloch surface waves. However, azimuthally generated Bloch surface waves have enhanced angular sensitivity compared to conventional polar angle coupled modes, which makes them appropriate for detecting tiny variations in surface refractive index due to the addition of nano-particles such as protein molecules.
Energy Technology Data Exchange (ETDEWEB)
Yasukawa, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)
1997-10-01
In order to avoid negative wave resistance (which is physically incomprehensible) generated in calculating wave resistance by using the Rankine source method, a proposal was made on a wave resistance calculation method using the Kochin function which describes behavior of speed potential in regions far apart from a hull. The Baba`s condition was used as a free surface condition for the speed potential which expresses wave motions around a hull. This has allowed a new Kochin function which uses as unknown the speed potential on the hull surface and the free surface near the hull to be defined and combined with the Rankine source method. A comparison was made between the calculated values for wave resistance, hull subsidence and trim change of an ore transporting vessel (SR107 type of ship) in a fully loaded condition and the result of water tank tests. The wave resistance values derived from pressure integration have all become negative when the Froude number is from 0.1 to 0.2, while no negative resistance has appeared in the calculations by using the Kochin function, but the result has agreed with that of the water tank tests. Accuracy of the calculations at low speeds was improved. The trim change in the calculations was slightly smaller than that in the water tank tests. The subsidence showed a good agreement. 7 refs., 1 fig.
Zhong, Tao; Wu, Xing-Gang; Huang, Tao
2016-07-01
The low-energy and high-energy behavior of the pion-photon transition form factor F_{π γ }(Q^2) are sensitive to the transverse and longitudinal distributions of the pion wave function, respectively. A careful study of F_{π γ }(Q^2) shall thus provide helpful constraints on the properties of the pion wave function. In this paper, we present a combined analysis of the data on F_{π γ }(Q^2) reported by the CELLO, the CLEO, the BABAR, and the BELLE Collaborations. It is performed by using the method of least squares. By using the combined measurements of the BELLE and CLEO Collaborations, the pion wave function longitudinal and transverse behavior can be fixed to a certain degree, i.e. we obtain β in [0.691,0.757] GeV and B in [0.00,0.235] for P_{χ ^2} ≥ 90 %, where β and B are two parameters of a convenient pion wave function model. It is noted that the distribution amplitude of such a pion wave function can mimic various longitudinal behaviors, as suggested in the literature under a proper choice of parameters. We observe that the CELLO, CLEO, and BELLE data are consistent with each other, all of which prefer the asymptotic-like distribution amplitude; while the BABAR data prefers a more broad distribution amplitude, such as the CZ-like one.
DTM: Deformable Template Matching
Lee, Hyungtae; Kwon, Heesung; Robinson, Ryan M.; Nothwang, William D.
2016-01-01
A novel template matching algorithm that can incorporate the concept of deformable parts, is presented in this paper. Unlike the deformable part model (DPM) employed in object recognition, the proposed template-matching approach called Deformable Template Matching (DTM) does not require a training step. Instead, deformation is achieved by a set of predefined basic rules (e.g. the left sub-patch cannot pass across the right patch). Experimental evaluation of this new method using the PASCAL VO...
L2 discretization of Sturmian wave functions for Coulomb-like potentials
Frapiccini, A. L.; Gonzalez, V. Y.; Randazzo, J. M.; Colavecchia, F. D.; Gasaneo, G.
In this work we introduce a method to construct Sturmian functions for general interaction potentials in two-body problems. We expand these Sturmians on a finite L2 space, using N Laguerre basis functions to obtain a discrete set of eigenvalues for positive and negative energies. Orthogonality and closure relations are thus rewritten for these expansions; completeness is achieved through increasing the basis size. We apply the method to the Coulomb and Herman and Skillman potential. We study the behavior of the functions obtained and their convergence for an overall range of energies. The Sturmian functions are applied to solve the Schrödinger equation for an active electron in a He-like system.
Impedance-matched Marx generators
Directory of Open Access Journals (Sweden)
W. A. Stygar
2017-04-01
Full Text Available We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs. The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with LC time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22-Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19-Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.
Impedance-matched Marx generators
Stygar, W. A.; LeChien, K. R.; Mazarakis, M. G.; Savage, M. E.; Stoltzfus, B. S.; Austin, K. N.; Breden, E. W.; Cuneo, M. E.; Hutsel, B. T.; Lewis, S. A.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Reisman, D. B.; Sceiford, M. E.; Wisher, M. L.
2017-04-01
We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs). The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with L C time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22 -Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19 -Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.
Nano-plasmonic near field phase matching of attosecond pulses.
Shaaran, Tahir; Nicolas, Rana; Iwan, Bianca; Kovacev, Milutin; Merdji, Hamed
2017-07-25
Nano-structures excited by light can enhance locally the electric field when tuned to plasmonic resonances. This phenomenon can be used to boost non-linear processes such as harmonic generation in crystals or in gases, Raman excitation, and four wave mixing. Here we present a theoretical investigation of the near-field phase matching of attosecond pulses emitted by high-order harmonic generation (HHG) of an atom immersed in a multi-cycle femtosecond infrared laser field and a spatially inhomogeneous plasmonic field. We demonstrate that the spatial inhomogeneity factor of the plasmonic field strongly affects the electron trajectory and recombination time which can be used to control the attosecond emission. For further insight into the plasmonic field effect, we monitor the phase of each quantum path as a function of the inhomogeneity strength. Moreover, we investigate the attosecond emission as a function of near-field phase matching effects. This is achieved by calculating the coherent field superposition of attosecond pulses emitted from various intensities or field inhomogeneities. Finally, far-field and near-field phase matching effects are combined to modulate the harmonic spectral phase towards the emission of a single attosecond pulse.
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available In the solution of boundary value problems, usually zero eigenvalue is ignored. This case also happens in calculating the eigenvalues of matrices, so that we would often like to find the nonzero solutions of the linear system A X = λ X when λ ≠ 0 . But λ = 0 implies that det A = 0 for X ≠ 0 and then the rank of matrix A is reduced at least one degree. This comment can similarly be stated for boundary value problems. In other words, if at least one of the eigens of equations related to the main problem is considered zero, then one of the solutions will be specified in advance. By using this note, first we study a class of special functions and then apply it for the potential, heat, and wave equations in spherical coordinate. In this way, some practical examples are also given.
Kwato-Njock, K
2002-01-01
A search is conducted for the determination of expectation values of r sup q between Dirac and quasirelativistic radial wave functions in the quantum-defect approximation. The phenomenological and supersymmetry-inspired quantum-defect models which have proven so far to yield accurate results are used. The recursive structure of formulae derived on the basis of the hypervirial theorem enables us to develop explicit relations for arbitrary values of q. Detailed numerical calculations concerning alkali-metal-like ions of the Li-, Na- and Cu-iso electronic sequences confirm the superiority of supersymmetry-based quantum-defect theory over quantum-defect orbital and exact orbital quantum number approximations. It is also shown that relativistic rather than quasirelativistic treatment may be used for consistent inclusion of relativistic effects.
Talebi, Nahid
2017-10-01
Investigating the interaction of electron beams with materials and light has been a field of research for more than a century. The field was advanced theoretically by the rise of quantum mechanics and technically by the introduction of electron microscopes and accelerators. It is possible nowadays to uncover a multitude of information from electron-induced excitations in matter by means of advanced techniques like holography, tomography, and, most recently, photon-induced near-field electron microscopy. The question is whether the interaction can be controlled in an even, more efficient way in order to unravel important questions like modal decomposition of the electron-induced polarization by performing experiments with better spatial, temporal, and energy resolutions. This review discusses recent advances in controlling electron and light interactions at the nanoscale. Theoretical and numerical aspects of the interaction of electrons with nanostructures and metamaterials will be discussed with the aim of understanding the mechanisms of radiation in the interaction of electrons with even more sophisticated structures. Based on these mechanisms of radiation, state-of-the art and novel electron-driven few-photon sources will be discussed. Applications of such sources to gain an understanding of quantum optical effects and also to perform spectral interferometry with electron microscopes will be covered. In an inverse approach, as in the case of the inverse Smith-Purcell effect, laser-induced excitations of nanostructures can cause electron beams traveling in the near-field of such structures to accelerate, provided a synchronization criterion is satisfied. This effect is the basis for linear dielectric and metallic electron accelerators. Moreover, acceleration is accompanied by bunching of the electrons. When single electrons are considered, an efficient design of nanostructures can lead to the shaping of the electron wave function travelling adjacent to them, for
Luo, Zhen; Ma, Yingjin; Liu, Chungen; Ma, Haibo
2017-10-10
We improve the methodology to construct a complete active space-configuration interaction (CAS-CI) expansion for density-matrix renormalization group (DMRG) wave functions using a matrix-product state representation, inspired by the sampling-reconstructed CAS [SR-CAS; Boguslawski , K. ; J. Chem. Phys. 2011 , 134 , 224101 ] algorithm. In our scheme, the genetic algorithm, in which the "crossover" and "mutation" processes can be optimized based on quantum information theory, is employed when reconstructing a CAS-CI-type wave function in the Hilbert space. Analysis of results for ground and excited state wave functions of conjugated molecules, transition metal compounds, and a lanthanide complex illustrate that our scheme is very efficient for searching the most important CI expansions in large active spaces.
Directory of Open Access Journals (Sweden)
Naoto Miura
2016-01-01
Full Text Available Clinical studies on application of functional electrical stimulation (FES to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES.
Miura, Naoto; Watanabe, Takashi
2016-01-01
Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES.
Nielsen, Richard A.
2016-01-01
This article shows how statistical matching methods can be used to select "most similar" cases for qualitative analysis. I first offer a methodological justification for research designs based on selecting most similar cases. I then discuss the applicability of existing matching methods to the task of selecting most similar cases and…
Ontology Matching Across Domains
2010-05-01
matching include GMO [1], Anchor-Prompt [2], and Similarity Flooding [3]. GMO is an iterative structural matcher, which uses RDF bipartite graphs to...AFRL under contract# FA8750-09-C-0058. References [1] Hu, W., Jian, N., Qu, Y., Wang, Y., “ GMO : a graph matching for ontologies”, in: Proceedings of
A pseudo-matched filter for chaos.
Cohen, Seth D; Gauthier, Daniel J
2012-09-01
A matched filter maximizes the signal-to-noise ratio of a signal. In the recent work of Corron et al. [Chaos 20, 023123 (2010)], a matched filter is derived for the chaotic waveforms produced by a piecewise-linear system. This system produces a readily available binary symbolic dynamics that can be used to perform correlations in the presence of large amounts of noise using the matched filter. Motivated by these results, we describe a pseudo-matched filter, which operates similarly to the original matched filter. It consists of a notch filter followed by a first-order, low-pass filter. We compare quantitatively the matched filter's performance to that of our pseudo-matched filter using correlation functions. On average, the pseudo-matched filter performs with a correlation signal-to-noise ratio that is 2.0 dB below that of the matched filter. Our pseudo-matched filter, though somewhat inferior in comparison to the matched filter, is easily realizable at high speed (>1 GHz) for potential radar applications.
Directory of Open Access Journals (Sweden)
Prem Parkash Gupta
2013-01-01
Full Text Available Objective: To assess sub-clinical cognitive dysfunctions in stable chronic obstructive pulmonary disease (COPD patients having no hypoxemia vs. age-matched healthy volunteers using (i an electrophysiological test: Auditory event related potential, P300 test and (ii a questionnaire tool: Mini-mental state examination (MMSE questionnaire. Materials and Methods: Eighty male subjects were included: 40 stable COPD patients (smoking history >20 pack years and 40 healthy volunteers (HVs. Age, duration of illness, smoking pack years, and spirometric indices were assessed. MMSE scores were evaluated in these groups. Latency of P300 wave and amplitude of P300 wave were studied in both groups to detect P300 abnormalities in COPD group. Correlations of P300 abnormalities with patient characteristic parameters and MMSE scores were assessed. In addition, individual COPD patients having significant cognitive dysfunctions beyond cut-off value of 99 th percentile of HVs were analyzed. Results: We observed significantly prolonged P300 latency ( P 0.05 for all. Conclusions: Our study explores cognitive dysfunctions in stable COPD patients with no hypoxemia. This study highlights the relative importance of using MMSE and P300. Cognitive dysfunctions were detected both by MMSE and P300; however, MMSE abnormalities were more frequent compared to P300 abnormalities (27/40 vs. 10/40 in COPD patients.
Energy Technology Data Exchange (ETDEWEB)
Theiler, James P [Los Alamos National Laboratory
2009-01-01
Following an analogous distinction in statistical hypothesis testing, we investigate variants of machine learning where the training set comes in matched pairs. We demonstrate that even conventional classifiers can exhibit improved performance when the input data has a matched-pair structure. Online algorithms, in particular, converge quicker when the data is presented in pairs. In some scenarios (such as the weak signal detection problem), matched pairs can be generated from independent samples, with the effect not only doubling the nominal size of the training set, but of providing the structure that leads to better learning. A family of 'dipole' algorithms is introduced that explicitly takes advantage of matched-pair structure in the input data and leads to further performance gains. Finally, we illustrate the application of matched-pair learning to chemical plume detection in hyperspectral imagery.
Chorus Wave Modulation of Langmuir Waves in the Radiation Belts
Li, Jinxing; Bortnik, Jacob; An, Xin; Li, Wen; Thorne, Richard M.; Zhou, Meng; Kurth, William S.; Hospodarsky, George B.; Funsten, Herbert O.; Spence, Harlan E.
2017-12-01
Using high-resolution waveforms measured by the Van Allen Probes, we report a novel observation in the radiation belts. Namely, we show that multiband, discrete, rising-tone whistler mode chorus emissions exhibit a one-to-one correlation with Langmuir wave bursts. Moreover, the periodic Langmuir wave bursts are generally observed at the phase location where the chorus wave E|| component is oriented opposite to its propagation direction. The electron measurements show a beam in phase space density at the particle velocity that matches the parallel phase velocity of the chorus waves. Based on this evidence, we conclude that the chorus waves accelerate the suprathermal electrons via Landau resonance and generate a localized electron beam in phase space density. Consequently, the Langmuir waves are excited locally and are modulated by the chorus wave phase. This microscale interaction between chorus waves and high-frequency electrostatic waves provides a new insight into the nonlinear wave-particle interaction process.
Robust Wave Resource Estimation
DEFF Research Database (Denmark)
Lavelle, John; Kofoed, Jens Peter
2013-01-01
An assessment of the wave energy resource at the location of the Danish Wave Energy test Centre (DanWEC) is presented in this paper. The Wave Energy Converter (WEC) test centre is located at Hanstholm in the of North West Denmark. Information about the long term wave statistics of the resource...... is necessary for WEC developers, both to optimise the WEC for the site, and to estimate its average yearly power production using a power matrix. The wave height and wave period sea states parameters are commonly characterized with a bivariate histogram. This paper presents bivariate histograms and kernel...... density estimates of the PDF as a function both of Hm0 and Tp, and Hm0 and T0;2, together with the mean wave power per unit crest length, Pw, as a function of Hm0 and T0;2. The wave elevation parameters, from which the wave parameters are calculated, are filtered to correct or remove spurious data...
Effective anisotropy through traveltime and amplitude matching
Wang, Hui
2014-08-05
Introducing anisotropy to seismic wave propagation reveals more realistic physics of our Earth\\'s subsurface as compared to the isotropic assumption. However wavefield modeling, the engine of seismic inverse problems, in anisotropic media still suffers from computational burdens, in particular with complex anisotropy such as transversely isotropic (TI) and Orthorhombic anisotropy. We develop effective isotropic velocity and density models to package the effects of anisotropy such that the wave propagation behavior using these effective models approximate those of the original anisotropic model. We build these effective models through the high frequency asymptotic approximation based on the eikonal and transport equations. We match the geometrical behavior of the wave-fields, given by traveltimes, from the anisotropic and isotropic eikonal equations. This matching yields the effective isotropic velocity that approximates the kinematics of the anisotropic wavefield. Equivalently, we calculate the effective densities by equating the anisotropic and isotropic transport equations. The effective velocities and densities are then fed into the isotropic acoustic variable density wave equation to obtain cheaper anisotropic wavefields. We justify our approach by testing it on an elliptical anisotropic model. The numerical results demonstrate a good matching of both traveltime and amplitude between anisotropic and effective isotropic wavefields.
Brashier, Bill; Salvi, Sundeep
2015-03-01
Measuring lung function is an important component in the decision making process for patients with obstructive airways disease (OAD). Not only does it help in arriving at a specific diagnosis, but it also helps in evaluating severity so that appropriate pharmacotherapy can be instituted, it helps determine prognosis and it helps evaluate response to therapy. Spirometry is currently the most commonly performed lung function test in clinical practice and is considered to be the gold standard diagnostic test for asthma and COPD. However, spirometry is not an easy test to perform because the forceful expiratory and inspiratory manoeuvres require good patient co-operation. Children aged <5 years, elderly people and those with physical and cognitive limitations cannot perform spirometry easily.
Schwerdtfeger, Peter; Lein, Matthias; Krawczyk, Robert P; Jacob, Christoph R
2008-03-28
Quantum theoretical calculations are presented for CO attached to charged and neutral Au and Au(2) with the aim to test the performance of currently applied density functional theory (DFT) by comparison with accurate wave-function based results. For this, we developed a compact sized correlation-consistent valence basis set which accompanies a small-core energy-consistent scalar relativistic pseudopotential for gold. The properties analyzed are geometries, dissociation energies, vibrational frequencies, ionization potentials, and electron affinities. The important role of the basis-set superposition error is addressed which can be substantial for the negatively charged systems. The dissociation energies decrease along the series Au(+)-CO, Au-CO, and Au(-)-CO and as well as along the series Au(2)(+)-CO, Au(2)-CO, and Au(2)(-)-CO. As one expects, a negative charge on gold weakens the carbon oxygen bond considerably, with a consequent redshift in the CO stretching frequency when moving from the positively charged to the neutral and the negatively charged gold atom or dimer. We find that the different density functional approximations applied are not able to correctly describe the rather weak interaction between CO and gold, thus questioning the application of DFT to CO adsorption on larger gold clusters or surfaces.
Deymier, Pierre A; Runge, Keith; Deymier, Martin J; Hoying, James B; Vasseur, Jérôme O
2010-10-01
We present a Green's function-based perturbative approach to solving nonlinear reaction-diffusion problems in networks of endothelial cells. We focus on a single component (Ca2+), piecewise nonlinear model of endoplasmic calcium dynamics and trans-membrane diffusion. The decoupling between nonlinear reaction dynamics and the linear diffusion enables the calculation of the diffusion part of the Green's function for network of cells with nontrivial topologies. We verify analytically and then numerically that our approach leads to the known transition from propagation of calcium front to failure of propagation when the diffusion rate is varied relative to the reaction rates. We then derive the Green's function for a semi-infinite chain of cells with various boundary conditions. We show that the calcium dynamics of cells in the vicinity of the end of the semi-infinite chain is strongly dependent on the boundary conditions. The behavior of the semi-infinite chain with absorbing boundary conditions, a simple model of a multicellular structure with an end in contact with the extracellular matrix, suggests behavioral differentiation between cells at the end and cells embedded within the chain.
Probabilistic seismic history matching using binary images
Davolio, Alessandra; Schiozer, Denis Jose
2018-02-01
Currently, the goal of history-matching procedures is not only to provide a model matching any observed data but also to generate multiple matched models to properly handle uncertainties. One such approach is a probabilistic history-matching methodology based on the discrete Latin Hypercube sampling algorithm, proposed in previous works, which was particularly efficient for matching well data (production rates and pressure). 4D seismic (4DS) data have been increasingly included into history-matching procedures. A key issue in seismic history matching (SHM) is to transfer data into a common domain: impedance, amplitude or pressure, and saturation. In any case, seismic inversions and/or modeling are required, which can be time consuming. An alternative to avoid these procedures is using binary images in SHM as they allow the shape, rather than the physical values, of observed anomalies to be matched. This work presents the incorporation of binary images in SHM within the aforementioned probabilistic history matching. The application was performed with real data from a segment of the Norne benchmark case that presents strong 4D anomalies, including softening signals due to pressure build up. The binary images are used to match the pressurized zones observed in time-lapse data. Three history matchings were conducted using: only well data, well and 4DS data, and only 4DS. The methodology is very flexible and successfully utilized the addition of binary images for seismic objective functions. Results proved the good convergence of the method in few iterations for all three cases. The matched models of the first two cases provided the best results, with similar well matching quality. The second case provided models presenting pore pressure changes according to the expected dynamic behavior (pressurized zones) observed on 4DS data. The use of binary images in SHM is relatively new with few examples in the literature. This work enriches this discussion by presenting a new
Benvenuti, Alberto C; Genchev, V; Khanov, A I; Stepanov, N; Vankov, P
2000-01-01
For most physical processes the tracks observed in the muon stations must be matched with the corresponding tracks in the inner tracker, the external muon system providing muon identification and triggering but the tracker points giving the precise momentum measurement at lower momenta. For high momenta the momentum resolution is much improved by the interconnection of inner and outer measurements. The matching of outer and inner measurements is more delicate in case of muons embedded in jets. A study of the matching procedure was carried out using samples of (b, anti b) jets at high Pt, requiring (b, anti b) -> mu decays.
Energy Technology Data Exchange (ETDEWEB)
Tokam, A K; Tabod, C T; Nyblade, A A; Julia, J; Wiens, D A; Pasyanos, M E
2010-02-18
Cameroon using 1-D shear wave velocity models obtained from the joint inversion of Rayleigh wave group velocities and P-receiver functions for 32 broadband seismic stations. From the 1-D shear wave velocity models, we obtain new insights into the composition and structure of the crust and upper mantle across Cameroon. After briefly reviewing the geological framework of Cameroon, we describe the data and the joint inversion method, and then interpret variations in crustal structure found beneath Cameroon in terms of the tectonic history of the region.
Hayati, Yazdan; Eskandari-Ghadi, Morteza
2018-02-01
An asymmetric three-dimensional thermoelastodynamic wave propagation with scalar potential functions is presented for an isotropic half-space, in such a way that the wave may be originated from an arbitrary either traction or heat flux applied on a patch at the free surface of the half-space. The displacements, stresses and temperature are presented within the framework of Biot's coupled thermoelasticity formulations. By employing a complete representation for the displacement and temperature fields in terms of two scalar potential functions, the governing equations of coupled thermoelasticity are uncoupled into a sixth- and a second-order partial differential equation in cylindrical coordinate system. By virtue of Fourier expansion and Hankel integral transforms, the angular and radial variables are suppressed respectively, and a 6{th}- and a 2{nd}-order ordinary differential equation in terms of depth are received, which are solved readily, from which the displacement, stresses and temperature fields are derived in transformed space by satisfying both the regularity and boundary conditions. By applying the inverse Hankel integral transforms, the displacements and temperature are numerically evaluated to determine the solutions in the real space. The numerical evaluations are done for three specific cases of vertical and horizontal time-harmonic patch traction and a constant heat flux passing through a circular disc on the surface of the half-space. It has been previously proved that the potential functions used in this paper are applicable from elastostatics to thermoelastodynamics. Thus, the analytical solutions presented in this paper are verified by comparing the results of this study with two specific problems reported in the literature, which are an elastodynamic problem and an axisymmetric quasi-static thermoelastic problem. To show the accuracy of numerical results, the solution of this study is also compared with the solution for elastodynamics exists in
Mclyman, W. T.
1979-01-01
Two circuit arrangements using ac and dc power source provide low-cost method for matching forward voltage drops of diodes and other semiconductors. Both circuits are simpler and less expensive than conventional, characteristic-curve tracers.
Infographic explaining NCI-COG Pediatric MATCH, a cancer treatment clinical trial for children and adolescents, from 1 to 21 years of age, that is testing the use of precision medicine for pediatric cancers.
Data Matching Imputation System
National Oceanic and Atmospheric Administration, Department of Commerce — The DMIS dataset is a flat file record of the matching of several data set collections. Primarily it consists of VTRs, dealer records, Observer data in conjunction...
Approximating quantum many-body wave functions using artificial neural networks
Cai, Zi; Liu, Jinguo
2018-01-01
In this paper, we demonstrate the expressibility of artificial neural networks (ANNs) in quantum many-body physics by showing that a feed-forward neural network with a small number of hidden layers can be trained to approximate with high precision the ground states of some notable quantum many-body systems. We consider the one-dimensional free bosons and fermions, spinless fermions on a square lattice away from half-filling, as well as frustrated quantum magnetism with a rapidly oscillating ground-state characteristic function. In the latter case, an ANN with a standard architecture fails, while that with a slightly modified one successfully learns the frustration-induced complex sign rule in the ground state and approximates the ground states with high precisions. As an example of practical use of our method, we also perform the variational method to explore the ground state of an antiferromagnetic J1-J2 Heisenberg model.
Lindén, J.; Lindberg, M.; Greggas, A.; Jylhävuori, N.; Norrgrann, H.; Lill, J. O.
2017-07-01
In addition to the main ingredients; sulfur, potassium chlorate and carbon, ordinary safety matches contain various dyes, glues etc, giving the head of the match an even texture and appealing color. Among the common reddish-brown matches there are several types, which after ignition can be attracted by a strong magnet. Before ignition the match head is generally not attracted by the magnet. An elemental analysis based on proton-induced x-ray emission was performed to single out iron as the element responsible for the observed magnetism. 57Fe Mössbauer spectroscopy was used for identifying the various types of iron-compounds, present before and after ignition, responsible for the macroscopic magnetism: Fe2O3 before and Fe3O4 after. The reaction was verified by mixing the main chemicals in the match-head with Fe2O3 in glue and mounting the mixture on a match stick. The ash residue after igniting the mixture was magnetic.
Modeling Regional Seismic Waves
1991-03-25
Shear waves are almost always observed from underground explosions. One can visualize many ways to convert explosion P waves into SV waves. An ob- vious...of the observed moment to the input source moment, Moba /Mo, as a function of the compressional velocities a, of the embedded sphere for different whole
Uemura, Wataru
2011-01-01
In this paper, we introduce a new representation of many body electron wave function and a few calculation results of the ground state energies of many body systems using that representation, which is systematically better than the Hartree-Fock approximation.
Energy Technology Data Exchange (ETDEWEB)
Fox, D.J.
1983-10-01
Analytic derivatives of the potential energy for Self-Consistent-Field (SCF) wave functions have been developed in recent years and found to be useful tools. The first derivative for configuration interaction (CI) wave functions is also available. This work details the extension of analytic methods to energy second derivatives for CI wave functions. The principal extension required for second derivatives is evaluation of the first order change in the CI wave function with respect to a nuclear perturbation. The shape driven graphical unitary group approach (SDGUGA) direct CI program was adapted to evaluate this term via the coupled-perturbed CI equations. Several iterative schemes are compared for use in solving these equations. The pilot program makes no use of molecular symmetry but the timing results show that utilization of molecular symmetry is desirable. The principles for defining and solving a set of symmetry adapted equations are discussed. Evaluation of the second derivative also requires the solution of the second order coupled-perturbed Hartree-Fock equations to obtain the correction to the molecular orbitals due to the nuclear perturbation. This process takes a consistently higher percentage of the computation time than for the first order equations alone and a strategy for its reduction is discussed.
Coupling Functions between Brain Waves: Significance of Opened/Closed Eyes
Directory of Open Access Journals (Sweden)
Lal Hussain
2017-08-01
Full Text Available In dynamical systems, the information flows converge or diverges in state space and is integrated or communicated between different cells assemblies termed as CFC. This process allows different oscillatory systems to communicate in accurate time, control and distribute the information flows in cell assemblies. The CF interactions allow the oscillatory rhythms to communicate in accurate time, and reintegrate the separated information. The intrinsic brain dynamics in Electroencephalography (EEG with eye - closed (EC and eye open (EO during resting states have been investigated to see the changes in brain complexity i.e. simple visual processing which are associated with increase in global dimension complexity. In order to study these changes in EEG, we have computed the coupling to see the inhibitory interneurons response and inter-regions functional connectivity differences between the eye conditions. We have investigated the fluctuations in EEG activities in low (delta, theta and high (alpha frequency brain oscillations. Coupling strength was estimated using Dynamic Bayesian inference approach which can effectively detect the phase connectivity subject to the noise within a network of time varying coupled phase oscillators. Using this approach, we have seen that delta-alpha and theta-alpha CFC are more dominant in resting state EEG and applicable to multivariate network oscillator. It shows that alpha phase was dominated by low frequency oscillations i.e. delta and theta. These different CFC help us to investigate complex neuronal brain dynamics at large scale networks. We observed the local interactions at high frequencies and global interactions at low frequencies. The alpha oscillations are generated from both posterior and anterior origins whereas the delta oscillations found at posterior regions.
Energy Technology Data Exchange (ETDEWEB)
Valdes, Haydee; Pluhackova, Kristyna; Pitonak, Michal; Rezac, Jan; Hobza, Pavel
2008-03-13
A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A)—where F and W are of aromatic character—is presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbone–aromatic side chain intramolecular interaction. Consequently, an accurate theoretical study of these systems requires the use of a methodology covering properly the London dispersion forces. For this reason we have assessed the performance of the MP2, SCS-MP2, MP3, TPSS-D, PBE-D, M06-2X, BH&H, TPSS, B3LYP, tight-binding DFT-D methods and ff99 empirical force field compared to CCSD(T)/complete basis set (CBS) limit benchmark data. All the DFT techniques with a ‘-D’ symbol have been augmented by empirical dispersion energy while the M06-2X functional was parameterized to cover the London dispersion energy. For the systems here studied we have concluded that the use of the ff99 force field is not recommended mainly due to problems concerning the assignment of reliable atomic charges. Tight-binding DFT-D is efficient as a screening tool providing reliable geometries. Among the DFT functionals, the M06-2X and TPSS-D show the best performance what is explained by the fact that both procedures cover the dispersion energy. The B3LYP and TPSS functionals—not covering this energy—fail systematically. Both, electronic energies and geometries obtained by means of the wave-function theory methods compare satisfactorily with the CCSD(T)/CBS benchmark data.
Allam, A. A.; Schulte-Pelkum, V.; Ben-Zion, Y.; Tape, C.; Ruppert, N.; Ross, Z. E.
2017-11-01
We examine the structure of the Denali fault system in the crust and upper mantle using double-difference tomography, P-wave receiver functions, and analysis (spatial distribution and moveout) of fault zone head waves. The three methods have complementary sensitivity; tomography is sensitive to 3D seismic velocity structure but smooths sharp boundaries, receiver functions are sensitive to (quasi) horizontal interfaces, and fault zone head waves are sensitive to (quasi) vertical interfaces. The results indicate that the Mohorovičić discontinuity is vertically offset by 10 to 15 km along the central 600 km of the Denali fault in the imaged region, with the northern side having shallower Moho depths around 30 km. An automated phase picker algorithm is used to identify 1400 events that generate fault zone head waves only at near-fault stations. At shorter hypocentral distances head waves are observed at stations on the northern side of the fault, while longer propagation distances and deeper events produce head waves on the southern side. These results suggest a reversal of the velocity contrast polarity with depth, which we confirm by computing average 1D velocity models separately north and south of the fault. Using teleseismic events with M ≥ 5.1, we obtain 31,400 P receiver functions and apply common-conversion-point stacking. The results are migrated to depth using the derived 3D tomography model. The imaged interfaces agree with the tomography model, showing a Moho offset along the central Denali fault and also the sub-parallel Hines Creek fault, a suture zone boundary 30 km to the north. To the east, this offset follows the Totschunda fault, which ruptured during the M7.9 2002 earthquake, rather than the Denali fault itself. The combined results suggest that the Denali fault zone separates two distinct crustal blocks, and that the Totschunda and Hines Creeks segments are important components of the fault and Cretaceous-aged suture zone structure.
Directory of Open Access Journals (Sweden)
M. V. Tchernycheva
2017-01-01
Full Text Available Subject of Research. The paper deals with development outcomes for creation method of one-electron wave functions of complex atoms, relatively simple, symmetrical for all atom electrons and free from hard computations. The accuracy and resource intensity of the approach are focused on systematic calculations of cross sections and rate constants of elementary processes of inelastic collisions of atoms or molecules with electrons (ionization, excitation, excitation transfer, and others. Method. The method is based on a set of two iterative processes. At the first iteration step the Schrödinger equation was solved numerically for the radial parts of the electron wave functions in the potential of the atomic core self-consistent field. At the second iteration step the new approximationfor the atomic core field is created that uses found solutions for all one-electron wave functions. The solution optimization for described multiparameter problem is achieved by the use of genetic algorithm. The suitability of the developed method was verified by comparing the calculation results with numerous data on the energies of atoms in the ground and excited states. Main Results. We have created the run-time version of the program for creation of sets of one-electron wave functions and calculation of the cross sections and constants of collisional transition rates in the first Born approximation. The priori available information about binding energies of the electrons for any many-particle system for creation of semi-empirical refined solutions for the one-electron wave functions can be considered at any step of this procedure. Practical Relevance. The proposed solution enables a simple and rapid preparation of input data for the numerical simulation of nonlocal gas discharge plasma. The approach is focused on the calculation of discharges in complex gas mixtures requiring inclusion in the model of a large number of elementary collisional and radiation
Approaches for Stereo Matching
Directory of Open Access Journals (Sweden)
Takouhi Ozanian
1995-04-01
Full Text Available This review focuses on the last decade's development of the computational stereopsis for recovering three-dimensional information. The main components of the stereo analysis are exposed: image acquisition and camera modeling, feature selection, feature matching and disparity interpretation. A brief survey is given of the well known feature selection approaches and the estimation parameters for this selection are mentioned. The difficulties in identifying correspondent locations in the two images are explained. Methods as to how effectively to constrain the search for correct solution of the correspondence problem are discussed, as are strategies for the whole matching process. Reasons for the occurrence of matching errors are considered. Some recently proposed approaches, employing new ideas in the modeling of stereo matching in terms of energy minimization, are described. Acknowledging the importance of computation time for real-time applications, special attention is paid to parallelism as a way to achieve the required level of performance. The development of trinocular stereo analysis as an alternative to the conventional binocular one, is described. Finally a classification based on the test images for verification of the stereo matching algorithms, is supplied.
Gupta, Prem Parkash; Sood, Sushma; Atreja, Atulya; Agarwal, Dipti
2013-01-01
To assess sub-clinical cognitive dysfunctions in stable chronic obstructive pulmonary disease (COPD) patients having no hypoxemia vs. age-matched healthy volunteers using (i) an electrophysiological test: Auditory event related potential, P300 test and (ii) a questionnaire tool: Mini-mental state examination (MMSE) questionnaire. EIGHTY MALE SUBJECTS WERE INCLUDED: 40 stable COPD patients (smoking history >20 pack years) and 40 healthy volunteers (HVs). Age, duration of illness, smoking pack years, and spirometric indices were assessed. MMSE scores were evaluated in these groups. Latency of P300 wave and amplitude of P300 wave were studied in both groups to detect P300 abnormalities in COPD group. Correlations of P300 abnormalities with patient characteristic parameters and MMSE scores were assessed. In addition, individual COPD patients having significant cognitive dysfunctions beyond cut-off value of 99(th) percentile of HVs were analyzed. We observed significantly prolonged P300 latency (P P300 amplitude (P P300 latency, and 27/40 COPD patients had reduced MMSE scores beyond 99(th) percentile of HV. However, we did not observe any statistically significant correlation between P300 abnormalities and patients' characteristics or MMSE scores (P > 0.05 for all). Our study explores cognitive dysfunctions in stable COPD patients with no hypoxemia. This study highlights the relative importance of using MMSE and P300. Cognitive dysfunctions were detected both by MMSE and P300; however, MMSE abnormalities were more frequent compared to P300 abnormalities (27/40 vs. 10/40) in COPD patients.
Energy Technology Data Exchange (ETDEWEB)
Loth, S.
2007-10-26
This thesis reports measurements of single dopant atoms in III-V semiconductors with low temperature Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy (STS). It investigates the anisotropic spatial distribution of acceptor induced tunneling processes at the {l_brace}110{r_brace} cleavage planes. Two different tunneling processes are identified: conventional imaging of the squared acceptor wave function and resonant tunneling at the charged acceptor. A thorough analysis of the tip induced space charge layers identifies characteristic bias windows for each tunnel process. The symmetry of the host crystal's band structure determines the spatial distribution of the tunneling paths for both processes. Symmetry reducing effects at the surface are responsible for a pronounced asymmetry of the acceptor contrasts along the principal [001] axis. Uniaxial strain fields due to surface relaxation and spin orbit interaction of the tip induced electric field are discussed on the basis of band structure calculations. High-resolution STS studies of acceptor atoms in an operating p-i-n diode confirm that an electric field indeed changes the acceptor contrasts. In conclusion, the anisotropic contrasts of acceptors are created by the host crystal's band structure and concomitant symmetry reduction effects at the surface. (orig.)
Role of gravity in the collapse of a wave function: A probe into the Diósi-Penrose model
Bahrami, M.; Smirne, A.; Bassi, A.
2014-12-01
We investigate the Diósi-Penrose (DP) proposal for connecting the collapse of the wave function to gravity. The DP model needs a free parameter, acting as a cutoff to regularize the dynamics, and the predictions of the model highly depend on the value of this cutoff. The Compton wavelength of a nucleon seems to be the most reasonable cutoff value since it justifies the nonrelativistic approach. However, with this value, the DP model predicts an unrealistically high rate of energy increase. Thus, either one is forced to choose a much larger cutoff, which is not physically justified and totally arbitrary, or one needs to include dissipative effects in order to tame the energy increase. Taking the analogy with dissipative collisional decoherence seriously, we develop a dissipative generalization of the DP model. We show that even with dissipative effects, the DP model contradicts known physical facts, unless either the cutoff is kept artificially large or one limits the applicability of the model to massive systems. We also provide an estimation for the mass range of this applicability.
REDUCING THE LIKELIHOOD OF LONG TENNIS MATCHES
Directory of Open Access Journals (Sweden)
Tristan Barnett
2006-12-01
Full Text Available Long matches can cause problems for tournaments. For example, the starting times of subsequent matches can be substantially delayed causing inconvenience to players, spectators, officials and television scheduling. They can even be seen as unfair in the tournament setting when the winner of a very long match, who may have negative aftereffects from such a match, plays the winner of an average or shorter length match in the next round. Long matches can also lead to injuries to the participating players. One factor that can lead to long matches is the use of the advantage set as the fifth set, as in the Australian Open, the French Open and Wimbledon. Another factor is long rallies and a greater than average number of points per game. This tends to occur more frequently on the slower surfaces such as at the French Open. The mathematical method of generating functions is used to show that the likelihood of long matches can be substantially reduced by using the tiebreak game in the fifth set, or more effectively by using a new type of game, the 50-40 game, throughout the match
Boguslawski, Katharina; Tecmer, Paweł
2017-10-03
Wave functions restricted to electron-pair states are promising models to describe static/nondynamic electron correlation effects encountered, for instance, in bond-dissociation processes and transition-metal and actinide chemistry. To reach spectroscopic accuracy, however, the missing dynamic electron correlation effects that cannot be described by electron-pair states need to be included a posteriori. In this Article, we extend the previously presented perturbation theory models with an Antisymmetric Product of 1-reference orbital Geminal (AP1roG) reference function that allows us to describe both static/nondynamic and dynamic electron correlation effects. Specifically, our perturbation theory models combine a diagonal and off-diagonal zero-order Hamiltonian, a single-reference and multireference dual state, and different excitation operators used to construct the projection manifold. We benchmark all proposed models as well as an a posteriori Linearized Coupled Cluster correction on top of AP1roG against CR-CC(2,3) reference data for reaction energies of several closed-shell molecules that are extrapolated to the basis set limit. Moreover, we test the performance of our new methods for multiple bond breaking processes in the homonuclear N2, C2, and F2 dimers as well as the heteronuclear BN, CO, and CN(+) dimers against MRCI-SD, MRCI-SD+Q, and CR-CC(2,3) reference data. Our numerical results indicate that the best performance is obtained from a Linearized Coupled Cluster correction as well as second-order perturbation theory corrections employing a diagonal and off-diagonal zero-order Hamiltonian and a single-determinant dual state. These dynamic corrections on top of AP1roG provide substantial improvements for binding energies and spectroscopic properties obtained with the AP1roG approach, while allowing us to approach chemical accuracy for reaction energies involving closed-shell species.
Directory of Open Access Journals (Sweden)
Sabiha Abekhoukh
2017-04-01
Full Text Available Cytoplasmic FMRP interacting protein 1 (CYFIP1 is a candidate gene for intellectual disability (ID, autism, schizophrenia and epilepsy. It is a member of a family of proteins that is highly conserved during evolution, sharing high homology with its Drosophila homolog, dCYFIP. CYFIP1 interacts with the Fragile X mental retardation protein (FMRP, encoded by the FMR1 gene, whose absence causes Fragile X syndrome, and with the translation initiation factor eIF4E. It is a member of the WAVE regulatory complex (WRC, thus representing a link between translational regulation and the actin cytoskeleton. Here, we present data showing a correlation between mRNA levels of CYFIP1 and other members of the WRC. This suggests a tight regulation of the levels of the WRC members, not only by post-translational mechanisms, as previously hypothesized. Moreover, we studied the impact of loss of function of both CYFIP1 and FMRP on neuronal growth and differentiation in two animal models – fly and mouse. We show that these two proteins antagonize each other's function not only during neuromuscular junction growth in the fly but also during new neuronal differentiation in the olfactory bulb of adult mice. Mechanistically, FMRP and CYFIP1 modulate mTor signaling in an antagonistic manner, likely via independent pathways, supporting the results obtained in mouse as well as in fly at the morphological level. Collectively, our results illustrate a new model to explain the cellular roles of FMRP and CYFIP1 and the molecular significance of their interaction.
Bellahsene, Zohra; Rahm, Erhard
2011-01-01
Requiring heterogeneous information systems to cooperate and communicate has now become crucial, especially in application areas like e-business, Web-based mash-ups and the life sciences. Such cooperating systems have to automatically and efficiently match, exchange, transform and integrate large data sets from different sources and of different structure in order to enable seamless data exchange and transformation. The book edited by Bellahsene, Bonifati and Rahm provides an overview of the ways in which the schema and ontology matching and mapping tools have addressed the above requirements
Ultrasonic guided wave nondestructive evaluation using generalized anisotropic interface waves
Gardner, Michael D.
The motivation for this work is a goal to inspect interfaces between thick layers of materials that can be anisotropic. The specific application is a thick composite bonded to a metal substrate. The interface is inspected for disbonds between the metal and composite. The large thickness allows the problem to be modeled as a half space. The theory behind guided waves in plates is presented. This theory includes the calculation and analysis of dispersion curves and the resulting wave structure. It is noted that for high frequency-thickness values, certain modes will converge to the half-space waves, e.g. the Rayleigh wave and the Stoneley wave. Points of high energy, especially shear energy, at the interface are desirable for interfacial inspection. Therefore, the wave structure for all modes and frequencies is searched for ideal inspection points. Interface waves are inherently good modes to use for interface inspection. Results from the dispersion curves and wave structures are verified in the finite element model software package called Abaqus. It is confirmed that the group speeds and wave structures of the modes match the predicted values. A theoretical development of interface waves is given wherein Rayleigh, Stoneley, and generalized interface waves are discussed. This is applied to both isotropic and anisotropic materials. It is shown that the Stoneley wave only exists for a certain range of material parameters. Because the Stoneley wave is the interface wave between two solid half spaces, it might appear that only certain pairs of solids would allow for inspection via interface wave. However, it is shown that for perturbations of the Stoneley-wave-valid material properties, interface waves which leak energy away from the interface can still propagate. They can also be used for inspection. Certain choices of materials will leak less energy and will therefore allow for longer inspection distances. The solutions to the isotropic leaky wave problem exist on
Mari, Andrea; Morselli, Simone; Sessa, Francesco; Campi, Riccardo; Di Maida, Fabrizio; Greco, Isabella; Siena, Giampaolo; Tuccio, Agostino; Vittori, Gianni; Serni, Sergio; Carini, Marco; Minervini, Andrea
2018-02-13
To evaluate the surgical and functional outcomes of a matched-paired series of on-clamp vs off-clamp endoscopic robot-assisted simple enucleation (ERASE) and standardized renorraphy in a tertiary referral institution, to search for predictors of functional drop after surgery and to investigate the influence of off-clamp technique in patients presenting these characteristics. A matched-pair comparison of 120 on-clamp vs 120 off-clamp over 491 patients treated with ERASE was performed. Perioperative and functional outcomes were compared between groups. Patients treated with on-clamp and off-clamp technique had comparable complication and positive surgical margin rate. The off-clamp group had a significantly lower eGFR drop compared to the on-clamp group at 3rd postoperative day (POD) (1% vs 7%, p = 0.0001) and at 30th POD (2.5% vs 9%, p = 0.01) from baseline. This difference lost its statistical significance at 6th month and at last follow-up (median 40 months). At multivariable analysis the Charlson comorbidity index (OR 2.06, p 15% eGFR drop from baseline to last follow-up. In a subanalysis over 64 comorbid patients, those patients who underwent off-clamp ERASE had a significantly lower eGFR drop compared to the comorbid counterpart during the whole follow-up. The off-clamp ERASE is a safe surgical technique with a significantly lower renal function drop compared to on-clamp ERASE in the early perioperative time. Patients with comorbidity might represent a subgroup of patients having a functional benefit after off-clamp RAPN even in the long-term period. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.
2010-09-01
senstivity to the uppermost mantle shear wave structure and to velocity contrasts across the Moho (Gangopadhyay et al., 2007). The amplitudes and signal-to...uppermost mantle shear wave structure and to velocity contrasts across the Moho (Gangopadhyay et al., 2007). Mutually satisfying constraints imposed by
Wang, Bin; Qian, Zhenghua; Li, Nian; Sarraf, Hamid
2016-01-01
We propose the use of thickness-twist (TT) wave modes of an AT-cut quartz crystal plate resonator for measurement of material parameters, such as stiffness, density and material gradient, of a functionally graded material (FGM) layer on its surface, whose material property varies exponentially in thickness direction. A theoretical analysis of dispersion relations for TT waves is presented using Mindlin's plate theory, with displacement mode shapes plotted, and the existence of face-shear (FS) wave modes discussed. Through numerical examples, the effects of material parameters (stiffness, density and material gradient) on dispersion curves, cutoff frequencies and mode shapes are thoroughly examined, which can act as a theoretical reference for measurements of unknown properties of FGM layer. Copyright © 2015 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Ibral, Asmaa [Equipe d’Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B.P. 20 El Jadida Principale, El Jadida 24000 (Morocco); Laboratoire d’Instrumentation, Mesure et Contrôle, Département de Physique, Université Chouaïb Doukkali, B.P. 20 El Jadida Principale, El Jadida (Morocco); Zouitine, Asmae [Département de Physique, Ecole Nationale Supérieure d’Enseignement Technique, Université Mohammed V Souissi, B.P. 6207 Rabat-Instituts, Rabat (Morocco); Assaid, El Mahdi, E-mail: eassaid@yahoo.fr [Equipe d’Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B.P. 20 El Jadida Principale, El Jadida 24000 (Morocco); Laboratoire d’Instrumentation, Mesure et Contrôle, Département de Physique, Université Chouaïb Doukkali, B.P. 20 El Jadida Principale, El Jadida (Morocco); Feddi, El Mustapha [Département de Physique, Ecole Nationale Supérieure d’Enseignement Technique, Université Mohammed V Souissi, B.P. 6207 Rabat-Instituts, Rabat (Morocco); and others
2014-09-15
Ground state energy and wave function of a hydrogen-like off-centre donor impurity, confined anywhere in a ZnS/CdSe spherical core/shell nanostructure are determined in the framework of the envelope function approximation. Conduction band-edge alignment between core and shell of nanostructure is described by a finite height barrier. Dielectric constant mismatch at the surface where core and shell materials meet is taken into account. Electron effective mass mismatch at the inner surface between core and shell is considered. A trial wave function where coulomb attraction between electron and off-centre ionized donor is used to calculate ground state energy via the Ritz variational principle. The numerical approach developed enables access to the dependence of binding energy, coulomb correlation parameter, spatial extension and radial probability density with respect to core radius, shell radius and impurity position inside ZnS/CdSe core/shell nanostructure.
Patrick, Ellis; Buckley, Michael; Müller, Samuel; Lin, David M; Yang, Jean Y H
2015-09-01
In practice, identifying and interpreting the functional impacts of the regulatory relationships between micro-RNA and messenger-RNA is non-trivial. The sheer scale of possible micro-RNA and messenger-RNA interactions can make the interpretation of results difficult. We propose a supervised framework, pMim, built upon concepts of significance combination, for jointly ranking regulatory micro-RNA and their potential functional impacts with respect to a condition of interest. Here, pMim directly tests if a micro-RNA is differentially expressed and if its predicted targets, which lie in a common biological pathway, have changed in the opposite direction. We leverage the information within existing micro-RNA target and pathway databases to stabilize the estimation and annotation of micro-RNA regulation making our approach suitable for datasets with small sample sizes. In addition to outputting meaningful and interpretable results, we demonstrate in a variety of datasets that the micro-RNA identified by pMim, in comparison to simpler existing approaches, are also more concordant with what is described in the literature. This framework is implemented as an R function, pMim, in the package sydSeq available from http://www.ellispatrick.com/r-packages. jean.yang@sydney.edu.au Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
The effects of core-reflected waves on finite fault inversions with teleseismic body wave data
Qian, Yunyi; Ni, Sidao; Wei, Shengji; Almeida, Rafael; Zhang, Han
2017-11-01
Teleseismic body waves are essential for imaging rupture processes of large earthquakes. Earthquake source parameters are usually characterized by waveform analyses such as finite fault inversions using only turning (direct) P and SH waves without considering the reflected phases from the core-mantle boundary (CMB). However, core-reflected waves such as ScS usually have amplitudes comparable to direct S waves due to the total reflection from the CMB and might interfere with the S waves used for inversion, especially at large epicentral distances for long duration earthquakes. In order to understand how core-reflected waves affect teleseismic body wave inversion results, we develop a procedure named Multitel3 to compute Green's functions that contain turning waves (direct P, pP, sP, direct S, sS and reverberations in the crust) and core-reflected waves (PcP, pPcP, sPcP, ScS, sScS and associated reflected phases from the CMB). This ray-based method can efficiently generate synthetic seismograms for turning and core-reflected waves independently, with the flexibility to take into account the 3-D Earth structure effect on the timing between these phases. The performance of this approach is assessed through a series of numerical inversion tests on synthetic waveforms of the 2008 Mw7.9 Wenchuan earthquake and the 2015 Mw7.8 Nepal earthquake. We also compare this improved method with the turning-wave only inversions and explore the stability of the new procedure when there are uncertainties in a priori information (such as fault geometry and epicentre location) or arrival time of core-reflected phases. Finally, a finite fault inversion of the 2005 Mw8.7 Nias-Simeulue earthquake is carried out using the improved Green's functions. Using enhanced Green's functions yields better inversion results as expected. While the finite source inversion with conventional P and SH waves is able to recover large-scale characteristics of the earthquake source, by adding PcP and ScS phases
Optimal Packed String Matching
DEFF Research Database (Denmark)
Ben-Kiki, Oren; Bille, Philip; Breslauer, Dany
2011-01-01
instructions. The main string-matching instruction is available in commodity processors (i.e., Intel’s SSE4.2 and AVX Advanced String Operations); the other maximal-suffix instruction is only required during pattern preprocessing. In the absence of these two specialized instructions, we propose theoretically...
DEFF Research Database (Denmark)
Hartelius, Karsten; Carstensen, Jens Michael
2003-01-01
A method for locating distorted grid structures in images is presented. The method is based on the theories of template matching and Bayesian image restoration. The grid is modeled as a deformable template. Prior knowledge of the grid is described through a Markov random field (MRF) model which r...... signals in hybridization filters and (2) localization of knit units in textile samples....
Zhou, Feng; de la Torre, Fernando
2015-11-19
Graph matching (GM) is a fundamental problem in computer science, and it plays a central role to solve correspondence problems in computer vision. GM problems that incorporate pairwise constraints can be formulated as a quadratic assignment problem (QAP). Although widely used, solving the correspondence problem through GM has two main limitations: (1) the QAP is NP-hard and difficult to approximate; (2) GM algorithms do not incorporate geometric constraints between nodes that are natural in computer vision problems. To address aforementioned problems, this paper proposes factorized graph matching (FGM). FGM factorizes the large pairwise affinity matrix into smaller matrices that encode the local structure of each graph and the pairwise affinity between edges. Four are the benefits that follow from this factorization: (1) There is no need to compute the costly (in space and time) pairwise affinity matrix; (2) The factorization allows the use of a path-following optimization algorithm, that leads to improved optimization strategies and matching performance; (3) Given the factorization, it becomes straight-forward to incorporate geometric transformations (rigid and non-rigid) to the GM problem. (4) Using a matrix formulation for the GM problem and the factorization, it is easy to reveal commonalities and differences between different GM methods. The factorization also provides a clean connection with other matching algorithms such as iterative closest point; Experimental results on synthetic and real databases illustrate how FGM outperforms state-of-the-art algorithms for GM. The code is available at http://humansensing.cs.cmu.edu/fgm.
Characteristic Evolution and Matching
Directory of Open Access Journals (Sweden)
Winicour Jeffrey
2001-01-01
Full Text Available I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to current 3D codes that simulate binary black holes. A prime application of characteristic evolution is Cauchy-characteristic matching, which is also reviewed.
Context-dependent logo matching and recognition.
Sahbi, Hichem; Ballan, Lamberto; Serra, Giuseppe; Del Bimbo, Alberto
2013-03-01
We contribute, through this paper, to the design of a novel variational framework able to match and recognize multiple instances of multiple reference logos in image archives. Reference logos and test images are seen as constellations of local features (interest points, regions, etc.) and matched by minimizing an energy function mixing: 1) a fidelity term that measures the quality of feature matching, 2) a neighborhood criterion that captures feature co-occurrence/geometry, and 3) a regularization term that controls the smoothness of the matching solution. We also introduce a detection/recognition procedure and study its theoretical consistency. Finally, we show the validity of our method through extensive experiments on the challenging MICC-Logos dataset. Our method overtakes, by 20%, baseline as well as state-of-the-art matching/recognition procedures.
Wave Data Processing and Analysis, Part 2: Codes for Coupling GenCade and CMS-Wave
2013-09-01
matches the file name used in the CMS‐Wave *.sim file. B. Select CMS-Wave Observation Cells Step 1. Determine the location where breaking waves...Development Center. Lin, L., Z. Demirbilek, H. Mase , J. Zheng, and F. Yamada. 2008. CMS-Wave: A nearshore spectral wave processes model for coastal
Egilson, Snæfrídur T; Jakobsdóttir, Gunnhildur; Ólafsdóttir, Linda B
2017-04-01
Few studies have focused on home participation of high-functioning children with autism spectrum disorder. We employed a mixed-methods design to explore and compare parent perspectives on (1) participation of children with and without autism spectrum disorder in activities at home, (2) the environmental features and resources that affect these children's home participation and (3) the strategies parents use to help their children participate at home. The Participation and Environment Measure for Children and Youth (PEM-CY) was used to gather online survey and qualitative data from parents of 99 high-functioning children with autism spectrum disorder and 241 children without autism spectrum disorder. Independent sample t-tests and χ2 tests were used to explore differences between groups, and Cohen's d was calculated to examine effect sizes. Differences were obtained on all Participation and Environment Measure for Children and Youth dimensions but particularly when comparing parents' satisfaction and perceived environmental barriers to their children's participation. The qualitative analyses revealed that parents in both groups used similar strategies to facilitate their children's participation at home, although parents of children with autism spectrum disorder made use of more distinct modifications. Our results highlight the importance of environmental aspects and point to how practitioners can support families in their efforts to promote their child's participation at home.
[Propensity score matching in SPSS].
Huang, Fuqiang; DU, Chunlin; Sun, Menghui; Ning, Bing; Luo, Ying; An, Shengli
2015-11-01
To realize propensity score matching in PS Matching module of SPSS and interpret the analysis results. The R software and plug-in that could link with the corresponding versions of SPSS and propensity score matching package were installed. A PS matching module was added in the SPSS interface, and its use was demonstrated with test data. Score estimation and nearest neighbor matching was achieved with the PS matching module, and the results of qualitative and quantitative statistical description and evaluation were presented in the form of a graph matching. Propensity score matching can be accomplished conveniently using SPSS software.
Spin wave generation by surface acoustic waves
Li, Xu; Labanowski, Dominic; Salahuddin, Sayeef; Lynch, Christopher S.
2017-07-01
Surface acoustic waves (SAW) on piezoelectric substrates can excite spin wave resonance (SWR) in magnetostrictive films through magnetoelastic coupling. This acoustically driven SWR enables the excitation of a single spin wave mode with an in-plane wave vector k matched to the magnetoelastic wave vector. A 2D frequency domain finite element model is presented that fully couples elastodynamics, micromagnetics, and piezoelectricity with interface spin pumping effects taken into account. It is used to simulate SAW driven SWR on a ferromagnetic and piezoelectric heterostructure device with an interdigital transducer configuration. These results, for the first time, present the spatial distribution of magnetization components that, together with elastic wave, exponentially decays along the propagation direction due to magnetic damping. The results also show that the system transmission rate S21(dB) can be tuned by both an external bias field and the SAW wavevector. Acoustic spin pumping at magnetic film/normal metal interface leads to damping enhancement in magnetic films that decreases the energy absorption rate from elastic energy. This weakened interaction between the magnetic energy and elastic energy leads to a lower evanescence rate of the SAW that results in a longer distance propagation. With strong magnetoelastic coupling, the SAW driven spin wave is able to propagate up to 1200 μm. The results give a quantitative indication of the acoustic spin pumping contribution to linewidth broadening.
Coronal Waves and Oscillations
Directory of Open Access Journals (Sweden)
Nakariakov Valery M.
2005-07-01
Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.
Crilly, Mike; Coch, Christoph; Bruce, Margaret; Clark, Hazel; Williams, David
2007-08-01
Pulse wave analysis (PWA) using applanation tonometry is a non-invasive technique for assessing cardiovascular function. It produces three important indices: ejection duration index (ED%), augmentation index adjusted for heart rate (AIX@75), and subendocardial viability ratio (SEVR%). The aim of this study was to assess within- and between-observer repeatability of these measurements. After resting supine for 15 minutes, 20 ambulant patients (16 male) in sinus rhythm underwent four PWA measurements on a single occasion. Two nurses (A & B) independently and alternately undertook PWA measurements using the same equipment (Omron HEM-757; SphygmoCor with Millar hand-held tonometer) blind to the other nurse's PWA measurements. Within- and between-observer differences were analysed using the Bland-Altman ;limits of agreement' approach (mean difference +/- 2 standard deviations, 2SD). Mean age was 56 (blood pressure, BP 136/79; pulse rate 64). BP/PWA measurements remained stable during assessment. Based on the average of two PWA measurements the mean +/- 2SD between-observer difference in ED% was 0.3 +/- 2.0; AIX@75 1.0 +/- 3.9; and SEVR% 1.7 +/- 14.2. Based on a single PWA measurement the between-observer difference was ED% 0.3 +/- 3.3; AIX@75 1.7 +/- 6.9; and SEVR% 0.6 +/- 22.6. Within-observer differences for nurse-A were ED% 0.0 +/- 5.4; AIX@75 1.5 +/- 7.0; and SEVR% 1.7 +/- 39.0 (nurse-B: 0.1 +/- 3.8; 0.1 +/- 8.0; and 0.6 +/- 23.3, respectively). PWA demonstrates high levels of repeatability even when used by relatively inexperienced staff and has the potential to be included in the routine cardiovascular assessment of ambulant patients.
Directory of Open Access Journals (Sweden)
Stephen Fôn Hughes
Full Text Available PURPOSE: The number of patients undergoing shock wave lithotripsy (SWL in the UK for solitary unilateral kidney stones is increasing annually. The development of postoperative complications such as haematuria and sepsis following SWL is likely to increase. Comparing a range of biological markers with the aim of monitoring or predicting postoperative complications following SWL has not been extensively researched. The main purpose of this pilot-study was to test the hypothesis that SWL results in changes to haemostatic function. Subsequently, this pilot-study would form a sound basis to undertake future investigations involving larger cohorts. METHODS: Twelve patients undergoing SWL for solitary unilateral kidney stones were recruited. From patients (8 male and 4 females aged between 31-72 years (median-43 years, venous blood samples were collected pre-operatively (baseline, at 30, 120 and 240 minutes postoperatively. Specific haemostatic biomarkers [platelet counts, prothrombin time (PT, activated partial thromboplastin time (aPTT, fibrinogen, D-dimer, von Willebrand Factor (vWF, sE-selectin and plasma viscosity (PV] were measured. RESULTS: Platelet counts and fibrinogen concentration were significantly decreased following SWL (p = 0.027 and p = 0.014 respectively, while D-dimer and vWF levels significantly increased following SWL (p = 0.019 and p = 0.001 respectively. PT, APTT, sE-selectin and PV parameters were not significantly changed following SWL (p>0.05. CONCLUSIONS: Changes to specific biomarkers such as plasma fibrinogen and vWF suggest that these represent a more clinically relevant assessment of the extent of haemostatic involvement following SWL. Analysis of such markers, in the future, may potentially provide valuable data on "normal" response after lithotripsy, and could be expanded to identify or predict those patients at risk of coagulopathy following SWL. The validation and reliability will be assessed through the assessment of
Hudier, E. J.; Bahoura, M.
2012-12-01
Sea ice is a two-phase porous medium consisting of a solid matrix of pure ice and a salty liquid phase. At spring when ice permeability increases, it has been observed that pressure gradients induced at the ice-water interface upstream and downstream of pressure ridge keels can cause sea water and brine to be forced through the ice water boundary. It suggests that salt and heat fluxes through the bottom ice layers may be a major factor controlling the decay of an ice sheet. Knowing how water flows through the ice matrix is fundamental to a modeling of ocean-ice heat exchanges integrating the advective import/export of latent heat that result from melting/freezing within the ice. Permeability is the measurement of the ease with which fluids flow through a porous medium, however one of the most tricky to measure without altering the porosity of the sampled medium. To further complicate the challenge, horizontal and vertical permeability of the ice, referred as ice anisotropy, is significant. Acoustic wave propagation through porous media have been theorized to relate the acoustic velocity and attenuation to the physical properties of the tested material. It is a non-invasive technique, and as such could provide more reliable measurements of sea ice permeability than anything presently used. Simulations combining the Biot's and squirt flow mechanisms are performed to investigate the effect of permeability on the attenuation and phase velocity as a function of frequency. We first present the attenuation dispersion curves for an isotropic sea ice, then low-frequency and high-frequency limits are determined. Optimal frequency range and resolution requirements are evaluated for testing.
Scherrer, Arne; Sebastiani, Daniel; Gross, E K U; Vuilleumier, Rodolphe
2015-01-01
The nuclear velocity perturbation current-density theory (NVPT) for vibrational circular dichroism (VCD) is derived from the exact factorization of the electron-nuclear wave function. This new formalism offers an exact starting point to include correction terms to the Born-Oppenheimer (BO) form of the molecular wave function, similarly to the complete-adiabatic approximation. The corrections depend on a small parameter that, in a classical treatment of the nuclei, is identified as the nuclear velocity. Apart from proposing a rigorous basis for the NVPT, we show that the rotational strength, related to the intensity of the VCD signal, contain a new contribution beyond-BO that can be evaluated with the NVPT and that only arises when the exact factorization approach is employed. Numerical results are presented for chiral and non-chiral systems to test the validity of the approach.
Energy Technology Data Exchange (ETDEWEB)
Nakra Mohajer, Soukaina; El Harouny, El Hassan [Laboratoire de Physique de la Matière Condensée, Département de Physique, Faculté des Sciences, Université Abdelmalek Essaadi, B.P. 2121 M’Hannech II, 93030 Tétouan (Morocco); Ibral, Asmaa [Equipe d’Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida Principale, El Jadida (Morocco); Laboratoire d’Instrumentation, Mesure et Contrôle, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida Principale, El Jadida (Morocco); El Khamkhami, Jamal [Laboratoire de Physique de la Matière Condensée, Département de Physique, Faculté des Sciences, Université Abdelmalek Essaadi, B.P. 2121 M’Hannech II, 93030 Tétouan (Morocco); and others
2016-09-15
Eigenvalues equation solutions of a hydrogen-like donor impurity, confined in a hemispherical quantum dot deposited on a wetting layer and capped by an insulating matrix, are determined in the framework of the effective mass approximation. Conduction band alignments at interfaces between quantum dot and surrounding materials are described by infinite height barriers. Ground and excited states energies and wave functions are determined analytically and via one-dimensional finite difference approach in case of an on-center donor. Donor impurity is then moved from center to pole of hemispherical quantum dot and eigenvalues equation is solved via Ritz variational principle, using a trial wave function where Coulomb attraction between electron and ionized donor is taken into account, and by two-dimensional finite difference approach. Numerical codes developed enable access to variations of donor total energy, binding energy, Coulomb correlation parameter, spatial extension and radial probability density with respect to hemisphere radius and impurity position inside the quantum dot.
A Theory of Rerepresentation in Analogical Matching
2003-01-01
cause (higherPressure Beaker Vial) (flow Beaker Vial Water Pipe)) T2: (cause (hotterThan Coffee IceCube ) (flow Coffee IceCube ...Coffee IceCube ) from the earlier example requires rewriting both expressions in terms of a more general, dimensional-independent comparative (e.g...greaterThan (Temperature Coffee) (Temperature IceCube )) which will match because non-identical function matches are allowed by structure
Lin, Yi-Hsuan; Brady, Jacob P.; Forman-Kay, Julie D.; Chan, Hue Sun
2017-11-01
Biologically functional liquid–liquid phase separation of intrinsically disordered proteins (IDPs) is driven by interactions encoded by their amino acid sequences. Little is currently known about the molecular recognition mechanisms for distributing different IDP sequences into various cellular membraneless compartments. Pertinent physics was addressed recently by applying random-phase-approximation (RPA) polymer theory to electrostatics, which is a major energetic component governing IDP phase properties. RPA accounts for charge patterns and thus has advantages over Flory–Huggins (FH) and Overbeek–Voorn mean-field theories. To make progress toward deciphering the phase behaviors of multiple IDP sequences, the RPA formulation for one IDP species plus solvent is hereby extended to treat polyampholyte solutions containing two IDP species plus solvent. The new formulation generally allows for binary coexistence of two phases, each containing a different set of volume fractions ({φ }1,{φ }2) for the two different IDP sequences. The asymmetry between the two predicted coexisting phases with regard to their {φ }1/{φ }2 ratios for the two sequences increases with increasing mismatch between their charge patterns. This finding points to a multivalent, stochastic, ‘fuzzy’ mode of molecular recognition that helps populate various IDP sequences differentially into separate phase compartments. An intuitive illustration of this trend is provided by FH models, whereby a hypothetical case of ternary coexistence is also explored. Augmentations of the present RPA theory with a relative permittivity {ε }{{r}}(φ ) that depends on IDP volume fraction φ ={φ }1+{φ }2 lead to higher propensities to phase separate, in line with the case with one IDP species we studied previously. Notably, the cooperative, phase-separation-enhancing effects predicted by the prescriptions for {ε }{{r}}(φ ) we deem physically plausible are much more prominent than that entailed by common
Taylor, Ann M; Harris, Ashley D; Varnava, Alice; Phillips, Rhiannon; Hughes, Owen; Wilkes, Antony R; Hall, Judith E; Wise, Richard G
2016-02-01
Chronic musculoskeletal pain (CMSKP) is attentionally demanding, complex and multi-factorial; neuroimaging research in the population seen in pain clinics is sparse. A better understanding of the neural activity underlying attentional processes to pain related information compared to healthy controls may help inform diagnosis and management in the future. Blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) compared brain responses in patients with CMSKP (n = 15) and healthy controls (n = 14) while completing a modified Stroop task using pain-related, positive-emotional, and neutral control words. Response times in the Stroop task were no different for CMSKP patients compared with controls, but patients were less accurate in their responses to all word types. BOLD fMRI responses during presentation of pain-related words suggested increases in neural activation in patients compared to controls in regions previously reported as being involved in pain perception and emotion: the anterior cingulate cortex, insula and primary and secondary somatosensory cortex. No fMRI differences were seen between groups in response to positive or control words. Using this modified Stroop tasks, specific differences were identified in brain activity between CMSKP patients and controls in response to pain-related information using fMRI. This provided evidence of differences in the way that pain-related information is processed in those with chronic complex musculoskeletal pain that were not detectable using the behavioural measures of speed and accuracy. The study may be helpful in gaining new insights into the impact of attention in those living with chronic pain.
Energy Technology Data Exchange (ETDEWEB)
Diaz-Miguel Bermudez, E.
2010-07-01
The paradox of De Broglie thread serves as a simple way to introduce some issues concerning the interpretation statistics, comprehensiveness, locality and realism in the mechanics Quantum. Also discussed through the numerical solution of the Schrodinger equation, the strange and unexpected behavior of the wave functions of stationary states of a particles enclosed in a box when we attempt to divide by a suitable potential. (Author) 16 refs.
Margerin, Ludovic
2017-11-01
In this work, I propose to model the propagation of high-frequency seismic waves in the heterogeneous Earth by means of a coupled system of radiative transfer equations for P and S waves. The model describes the propagation of both coherent and diffuse waves in a statistically isotropic heterogeneous medium and takes into account key phenomena such as scattering conversions between propagation modes, scattering anisotropy and absorption. The main limitation of the approach lies in the neglect of the shear wave polarization information. The canonical case of a medium with uniform scattering and absorption properties is studied in details. Using an adjoint formalism, Green's functions (isotropic point source solutions) of the transport equation are shown to obey a reciprocity relation relating the P energy density radiated by an S source to the S energy density radiated by a P source. A spectral method of calculation of the Green's function is presented. Application of Fourier, Hankel and Legendre transforms to time, space and angular variables, respectively, turns the equation of transport into a numerically tractable penta-diagonal linear system of equations. The implementation of the spectral method is discussed in details and validated through one-to-one comparisons with Monte Carlo simulations. Numerical experiments in different propagation regimes illustrate that the ratio between the correlation length of heterogeneities and the incident wavelength plays a key role in the rate of stabilization of the P-to- S energy ratio in the coda. The results suggest that the rapid stabilization of energy ratios observed in the seismic coda is a signature of the broadband nature of crustal heterogeneities. The impact of the texture of the medium on both pulse broadening and generation of converted S wave arrivals by explosion sources is illustrated. The numerical study indicates that smooth media enhance the visibility of ballistic-like S arrivals from P sources.
Margerin, Ludovic
2017-07-01
In this work, I propose to model the propagation of high-frequency seismic waves in the heterogeneous Earth by means of a coupled system of radiative transfer equations for P and S waves. The model describes the propagation of both coherent and diffuse waves in a statistically isotropic heterogeneous medium and takes into account key phenomena such as scattering conversions between propagation modes, scattering anisotropy and absorption. The main limitation of the approach lies in the neglect of the shear wave polarization information. The canonical case of a medium with uniform scattering and absorption properties is studied in details. Using an adjoint formalism, Green's functions (isotropic point source solutions) of the transport equation are shown to obey a reciprocity relation relating the P energy density radiated by an S source to the S energy density radiated by a P source. A spectral method of calculation of the Green's function is presented. Application of Fourier, Hankel and Legendre transforms to time, space and angular variables, respectively, turns the equation of transport into a numerically tractable penta-diagonal linear system of equations. The implementation of the spectral method is discussed in details and validated through one-to-one comparisons with Monte Carlo simulations. Numerical experiments in different propagation regimes illustrate that the ratio between the correlation length of heterogeneities and the incident wavelength plays a key role in the rate of stabilization of the P-to-S energy ratio in the coda. The results suggest that the rapid stabilization of energy ratios observed in the seismic coda is a signature of the broadband nature of crustal heterogeneities. The impact of the texture of the medium on both pulse broadening and generation of converted S wave arrivals by explosion sources is illustrated. The numerical study indicates that smooth media enhance the visibility of ballistic-like S arrivals from P sources.
Fast algorithms for approximate circular string matching.
Barton, Carl; Iliopoulos, Costas S; Pissis, Solon P
2014-03-22
Circular string matching is a problem which naturally arises in many biological contexts. It consists in finding all occurrences of the rotations of a pattern of length m in a text of length n. There exist optimal average-case algorithms for exact circular string matching. Approximate circular string matching is a rather undeveloped area. In this article, we present a suboptimal average-case algorithm for exact circular string matching requiring time O(n). Based on our solution for the exact case, we present two fast average-case algorithms for approximate circular string matching with k-mismatches, under the Hamming distance model, requiring time O(n) for moderate values of k, that is k=O(m/logm). We show how the same results can be easily obtained under the edit distance model. The presented algorithms are also implemented as library functions. Experimental results demonstrate that the functions provided in this library accelerate the computations by more than three orders of magnitude compared to a naïve approach. We present two fast average-case algorithms for approximate circular string matching with k-mismatches; and show that they also perform very well in practice. The importance of our contribution is underlined by the fact that the provided functions may be seamlessly integrated into any biological pipeline. The source code of the library is freely available at http://www.inf.kcl.ac.uk/research/projects/asmf/.
The Crest Wing Wave Energy Device
DEFF Research Database (Denmark)
Kofoed, Jens Peter; Antonishen, Michael Patrick
This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave...
Job match and income distributions
Li, Honggang; Wang, Dahui; Chen, Xianggui
2004-10-01
This paper studies the income distributions from the view of job match. By numerical simulation, we present different income distributions cases with different degrees of job match. In particular, we analyze the probability distribution of individual income, and we also discuss the economic efficiency and economic equality in different job match cases. Our basic results are that different job matchs can change income distributions, and good job matchs can not only improve economic efficiency but also aggravate economic inequality.
Football match spectator sound exposure and effect on hearing: A ...
African Journals Online (AJOL)
Objectives. To determine (i) noise exposure levels of spectators at a FIFA 2010 designated training stadium during a premier soccer league match; and (ii) changes in auditory functioning after the match. Methods. This was a one-group pretest–post-test design of football spectators attending a premier soccer league match ...
Hybrid silicon mode-locked laser with improved RF power by impedance matching
Tossoun, Bassem; Derickson, Dennis; Srinivasan, Sudharsanan; Bowers, John
2015-02-01
We design and discuss an impedance matching solution for a hybrid silicon mode-locked laser diode (MLLD) to improve peak optical power coming from the device. In order to develop an impedance matching solution, a thorough measurement and analysis of the MLLD as a function of bias on each of the laser segments was carried out. A passive component impedance matching network was designed at the operating frequency of 20 GHz to optimize RF power delivery to the laser. The hybrid silicon laser was packaged together in a module including the impedance matching circuit. The impedance matching design resulted in a 6 dB (electrical) improvement in the detected modulation spectrum power, as well as approximately a 10 dB phase noise improvement, from the MLLD. Also, looking ahead to possible future work, we discuss a Step Recovery Diode (SRD) driven impulse generator, which wave-shapes the RF drive to achieve efficient injection. This novel technique addresses the time varying impedance of the absorber as the optical pulse passes through it, to provide optimum optical pulse shaping.
DEFF Research Database (Denmark)
Hedegård, Erik D.; Jensen, Hans Jørgen Aagaard; Knecht, Stefan
2013-01-01
Charge transfer excitations can be described within Time-Dependent Density Functional Theory (TD-DFT), not only by means of the Coulomb Attenuated Method (CAM) but also with a combination of wave function theory and TD-DFT based on range separation. The latter approach enables a rigorous formulat......Charge transfer excitations can be described within Time-Dependent Density Functional Theory (TD-DFT), not only by means of the Coulomb Attenuated Method (CAM) but also with a combination of wave function theory and TD-DFT based on range separation. The latter approach enables a rigorous...... formulation of multi-determinantal TD-DFT schemes where excitation classes, which are absent in conventional TD-DFT spectra (like for example double excitations), can be addressed. This paper investigates the combination of both the long-range Multi-Configuration Self-Consistent Field (MCSCF) and Second Order...... Polarization Propagator Approximation (SOPPA) ansätze with a short-range DFT (srDFT) description. We find that the combinations of SOPPA or MCSCF with TD-DFT yield better results than could be expected from the pure wave function schemes. For the Time-Dependent MCSCF short-range DFT ansatz (TD...
Takagi, Toshio; Kondo, Tsunenori; Yoshida, Kazuhiko; Kobayashi, Hirohito; Iizuka, Junpei; Okumi, Masayoshi; Ishida, Hideki; Tanabe, Kazunari
2017-12-11
To compare early postoperative renal function in transperitoneal robot-assisted laparoscopic partial nephrectomy (RAPN) for anterior and posterior renal tumors. This study included 227 patients who underwent transperitoneal RAPN for anterior or posterior renal tumors. Tumor position was defined by RENAL nephrometry score. To minimize selection bias between anterior and posterior tumors, patient variables were adjusted using 1:1 propensity score matching. Of the 227 patients, 125 were classified as having anterior tumors and 102 as having posterior tumors. After matching, 82 patients were included in each group. The mean preoperative estimated glomerular filtration rate (eGFR) was 66 mL/min/1.73 m2. The mean tumor size was 28 to 29 mm. The decrease in early postoperative nadir eGFR (-10% vs -4.0%, p = 0.0103) was significantly higher for posterior tumors than for anterior tumors. However, the difference improved 6 to 12 months after surgery (-6.0% vs -6.2%, p = 0.9564). The other surgical outcomes, including operative time, warm ischemia time (WIT), complications, surgical margin status, and length of hospital stay, were not significantly different between the two groups. In multivariate analysis of the entire cohort, posterior tumors (vs anterior tumor, odds ratio [OR]: 2.30, p = 0.0051), longer WIT (OR: 3.10, p = 0.0019), and high tumor complexity (vs low complexity, OR: 3.46, p = 0.0264) were independent predictors for development of a 10% decrease in early postoperative eGFR. Posterior tumors had a greater decrease in early postoperative nadir eGFR than anterior tumors, with equivalent surgical outcomes, including similar renal function, 6 to 12 months after surgery in the setting of transperitoneal RAPN.
Controllable transmission and total reflection through an impedance-matched acoustic metasurface
Mei, Jun
2014-12-02
A general design paradigm for a novel type of acoustic metasurface is proposed by introducing periodically repeated supercells on a rigid thin plate, where each supercell contains multiple cut-through slits that are filled with materials possessing different refractive indices but the same impedance as that of the host medium. When the wavelength of the incident wave is smaller than the periodicity, the direction of the transmitted wave with nearly unity transmittance can be chosen by engineering the phase discontinuities along the transverse direction. When the wavelength is larger than the periodicity, even though the metasurface is impedance matched to the host medium, most of the incident energy is reflected back and the remaining portion is converted into a surface-bound mode. We show that both the transmitted wave control and the high reflection with the surface mode excitation can be interpreted by a unified analytic model based on mode-coupling theory. Our general design principle not only supplies the functionalities of reflection-type acoustic metasurfaces, but also exhibits unprecedented flexibility and efficiency in various domains of wave manipulation for possible applications in fields like refracting, collimating, focusing or absorbing wave energy.
Random Euclidean matching problems in one dimension
Caracciolo, Sergio; D'Achille, Matteo; Sicuro, Gabriele
2017-10-01
We discuss the optimal matching solution for both the assignment problem and the matching problem in one dimension for a large class of convex cost functions. We consider the problem in a compact set with the topology both of the interval and of the circumference. Afterwards, we assume the points' positions to be random variables identically and independently distributed on the considered domain. We analytically obtain the average optimal cost in the asymptotic regime of very large number of points N and some correlation functions for a power-law-type cost function in the form c (z ) =zp , both in the p >1 case and in the p cost with the number of points is N-p/2 for the assignment and N-p for the matching when p >1 , whereas in both cases it is a constant when p <0 . Finally, our predictions are compared with the results of numerical simulations.
Çakır, Tuncay; Evcik, Fatma Deniz; Subaşı, Volkan; Demirdal, Ümit Seçil; Kavuncu, Vural
2015-09-01
The purpose of the study was to evaluate the relationship between sympathetic skin responses (SSR), electrodiagnostic reflex activities (F wave, H reflex), and functional capacity in post-stroke patients. The study comprised 40 hemiplegia patients (mean age 57.8 ± 10.9 years) and 40 healthy volunteers (mean age 557 ± 85 years). In electrophysiological studies, SSR, F wave and H reflex were evaluated and for the functional capacities of patients, FIM scores and Brunnstrom stages were calculated. There was no statistical significant difference between SSR latency and amplitude in the hemiplegic and non-hemiplegic extremities of patients (p > 0.05). SSR latency values of patients were higher than those of controls (p < 0.05). Amplitude values of paretic arms were significantly lower than the control group extremities (p < 0.05). There was a significant correlation between SSR amplitude values and FIM scores. A significant increase in H max/M max amplitude rate was detected in the affected side (p < 0.05) and F-wave mean latency values of the affected side were found to be significantly lower in the control group (p < 0.05).
Wu, Wenliang; Zhao, Hua; Xie, Bin; Liu, Haichun; Chen, Yunzhen; Jiao, Guangjun; Wang, Hongliang
2011-03-10
Transplantation of bone marrow-derived mesenchymal stromal cells (BMSCs) into the injured spinal cord may provide therapeutic benefit, but its application is limited by their poor survival and low differentiation rate into neurons. Electrical stimulation (ES) has been reported to promote survival and differentiation of the BMSCs. Therefore we investigated whether implanted spike wave ES could improve survival of BMSCs after transplantation and result in functional improvement in animals with spinal cord injury. Our results showed that the number and ratio of survived BMSCs near the lesion site were significantly increased in the BMSCs+ES-treated group as compared to BMSCs transplantation or ES treatment alone group. Furthermore, results from BBB scales, SSEP and DTI demonstrated a significant improved functional recovery in the BMSCs+ES group. This indicated that implanted spike wave ES could promote the bioactivity of BMSCs and their survival. This represents a new therapeutic potential of the combination of BMSCs transplantation with implanted spike wave ES to treat spinal cord injury. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Hietala, Vincent M.; Vawter, Gregory A.
1993-01-01
The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.
DEFF Research Database (Denmark)
This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...
Wave directional spectrum from array measurements
Digital Repository Service at National Institute of Oceanography (India)
Fernandes, A.A; Sarma, Y; Menon, H.B.
Using the method of Esteva (1976, 1977), whcih assumes that at the frequency band the waves approach from just a single "mean" wave direction, wave direction has been consistently, accurately and unambiguously evaluated as a function of frequency...
Kallosh, Renata
1994-01-01
We study the gravitational waves in the 10-dimensional target space of the superstring theory. Some of these waves have unbroken supersymmetries. They consist of Brinkmann metric and of a 2-form field. Sigma-model duality is applied to such waves. The corresponding solutions we call dual partners of gravitational waves, or dual waves. Some of these dual waves upon Kaluza-Klein dimensional reduction to 4 dimensions become equivalent to the conformo-stationary solutions of axion-dilaton gravity...
Deshpande, Akshaya; Mohan, Gollapally
2017-04-01
The northwestern Deccan volcanic province (NWDVP) of India, encompassing the Saurashtra peninsula and the adjoining Gulf of Cambay, is investigated through joint inversion of surface wave dispersion measurements and teleseis- mic P receiver functions, to estimate the crustal and shallow upper mantle shear wave velocity (Vs) structure. The Mw ˜ 7.7 Bhuj earthquake and the post Bhuj regional events, recorded during the period 2001-2010 at 7 stations along 37 source-receiver paths were used along with 35 teleseismic events. A joint curve fitting inversion technique is applied to obtain a best fit for the fundamental mode Rayleigh wave group velocity dispersion curves for time periods 5-50 s and high quality crustal P wave receiver functions obtained at each station. Significant crustal heterogeneity is observed within the study region with the average crustal Vs ranging from 3.5 km/s to 3.8 km/s with the paths cutting across the Gulf of Cambay exhibiting large reduction in shear wave velocities. Utilizing the average crustal Vs ≈ 3.66 km/s estimated for Saurashtra, together with the average crustal P wave velocity (Vp) ≈ 6.54 km/s derived independently through deep seismic sounding studies, yields a bulk Vp/Vs ratio of 1.786 or an equivalent crustal Poisson's ratio of 0.271. A major contribution to the high Poisson's ratio comes from the 12 to 16 km thick lower crustal layers with shear velocities ranging from 3.8 km/s to 4.19 km/s suggesting widespread magmatic underplating due to emplacement of mafic cumulates in the lower crust. The shallow uppermost mantle shear velocities are in the range 4.2-4.5 km/s averaging 4.36 km/ s, which is less than that observed for the Indian shield, indicating the effects of residual thermal anomaly. The variation in the crustal Vs, high Poisson's ratios and low upper mantle shear velocities reflect the thermal and compositional effects of the Deccan volcanism which are manifested in terms of pervasive presence of mafic dykes
Laufer, Y; Zilberman, R; Porat, R; Nahir, A M
2005-05-01
To examine the effects of pulsed short-wave diathermy (PSWD), delivered at an intensity sufficient to induce a thermal sensation and at an athermal intensity, in comparison with a placebo short-wave diathermy treatment, on reported pain, stiffness and functional ability and on mobility performance of patients with osteoarthritis of the knee. A placebo-controlled double-blind trial with sequential allocation of patients to different treatment groups. Outpatient physiotherapy department. One hundred and three consecutive patients, mean age 73.7 (+/-6.6) years with osteoarthritis of one or both knees for at least three months. All participants received three 20-min-long treatments per week for three weeks. One group received PSWD with mean power of 18 W (thermal effect), one group received PSWD with mean power of 1.8 W (athermal effect), and one group received sham short-wave diathermy treatment. Patients were assessed before the initial treatment, immediately following the last treatment, and at a three-month follow-up. Outcome measures included the WOMAC Osteoarthritis Index, which assessed reported pain, stiffness, and functional ability, and four measures of mobility performance: Timed Get Up and Go test (TGUG), stair-climbing, stair, descending and a 3-min walk. A difference across time was observed for the pain and stiffness categories of the WOMAC Osteoarthritis Index (p = 0.033 and p = 0.008, respectively), with no differences between groups. No other significant differences across time or between groups were observed in any of the other measures. The findings do not demonstrate pulsed short-wave diathermy, as it is utilized in clinical settings, to be effective in the treatment of osteoarthritis of the knee.
Bos, E H; Ten Have, M; van Dorsselaer, S; Jeronimus, B F; de Graaf, R; de Jonge, P
2018-01-14
The vulnerability hypothesis suggests that impairments after remission of depressive episodes reflect a pre-existing vulnerability, while the scar hypothesis proposes that depression leaves residual impairments that confer risk of subsequent episodes. We prospectively examined vulnerability and scar effects in mental and physical functioning in a representative Dutch population sample. Three waves were used from the Netherlands Mental Health Survey and Incidence Study-2, a population-based study with a 6-years follow-up. Mental and physical functioning were assessed with the Medical Outcomes Study Short Form (SF-36). Major depressive disorder (MDD) was assessed with the Composite International Diagnostic Interview 3.0. Vulnerability effects were examined by comparing healthy controls (n = 2826) with individuals who developed a first-onset depressive episode during first follow-up but did not have a lifetime diagnosis of MDD at baseline (n = 181). Scarring effects were examined by comparing pre- and post-morbid functioning in individuals who developed a depressive episode after baseline that was remitted at the third wave (n = 108). Both mental (B = -5.4, s.e. = 0.9, p morbidly (B = -5.1, s.e. = 2.1, p = 0.014), but this effect disappeared in adjusted analyses. Functional impairments after remission of depression seem to reflect a pre-existing vulnerability rather than a scar.
Element-by-element parallel spectral-element methods for 3-D teleseismic wave modeling
Liu, Shaolin
2017-09-28
The development of an efficient algorithm for teleseismic wave field modeling is valuable for calculating the gradients of the misfit function (termed misfit gradients) or Fréchet derivatives when the teleseismic waveform is used for adjoint tomography. Here, we introduce an element-by-element parallel spectral-element method (EBE-SEM) for the efficient modeling of teleseismic wave field propagation in a reduced geology model. Under the plane-wave assumption, the frequency-wavenumber (FK) technique is implemented to compute the boundary wave field used to construct the boundary condition of the teleseismic wave incidence. To reduce the memory required for the storage of the boundary wave field for the incidence boundary condition, a strategy is introduced to efficiently store the boundary wave field on the model boundary. The perfectly matched layers absorbing boundary condition (PML ABC) is formulated using the EBE-SEM to absorb the scattered wave field from the model interior. The misfit gradient can easily be constructed in each time step during the calculation of the adjoint wave field. Three synthetic examples demonstrate the validity of the EBE-SEM for use in teleseismic wave field modeling and the misfit gradient calculation.
A birefringent prism coupler in guided wave experiments.
Wang, H
1995-12-01
A rutile prism was used to excite guided waves in a CdS film. The wave vector matching condition was studied under the influence of prism's birefringence. Refractive indices and thickness of the film were determined.
Sparse window local stereo matching
Damjanovic, S.; van der Heijden, Ferdinand; Spreeuwers, Lieuwe Jan
2011-01-01
We propose a new local algorithm for dense stereo matching of gray images. This algorithm is a hybrid of the pixel based and the window based matching approach; it uses a subset of pixels from the large window for matching. Our algorithm does not suffer from the common pitfalls of the window based
Quantity precommitment and price matching
DEFF Research Database (Denmark)
Tumennasan, Norovsambuu
We revisit the question of whether price matching is anti-competitive in a capacity constrained duopoly setting. We show that the effect of price matching depends on capacity. Specifically, price matching has no effect when capacity is relatively low, but it benefits the firms when capacity is re...
Maltoni, Lucia; Posar, Annio; Parmeggiani, Antonia
2016-07-01
Continuous spike-waves during sleep (CSWS) are associated with several cognitive, neurological, and psychiatric disorders, which sometimes persist after CSWS disappearance. The purpose of this retrospective study was to investigate the correlation between general (clinical and instrumental) and neuropsychological findings in CSWS, to identify variables that predispose patients to a poorer long-term neuropsychological outcome. Patients with spikes and waves during sleep with a frequency ≥25/min (spikes and waves frequency index - SWFI) were enrolled. There were patients presenting abnormal EEG activity corresponding to the classic CSWS and patients with paroxysmal abnormalities during sleep sleep (ESWS). Clinical and instrumental features and neuropsychological findings during and after the spike and wave active phase period were considered. A statistical analysis was performed utilizing the Spearman correlation test and multivariate analysis. The study included 61 patients; the mean follow-up (i.e., the period between SWFI ≥25 first recording and last observation) was 7years and 4months. The SWFI correlated inversely with full and performance IQ during CSWS/ESWS. Longer-lasting SWFI ≥25 was related to worse results in verbal IQ and performance IQ after CSWS/ESWS disappearance. Other variables may influence the neuropsychological outcome, like age at SWFI ≥25 first recording, perinatal distress, pathologic neurologic examination, and antiepileptic drug resistance. This confirms that CSWS/ESWS are a complex pathology and that many variables contribute to its outcome. The SWFI value above all during CSWS/ESWS and long-lasting SWFI ≥25 after CSWS/ESWS disappearance are the most significant indexes that appear mostly to determine cognitive evolution. This finding underscores the importance of EEG recordings during sleep in children with a developmental disorder, even if seizures are not reported, as well as the importance of using therapy with an early
Lu, Zengbing; Yeung, Chi-Kong; Lin, Ge; Yew, David T W; Andrews, P L R; Rudd, John A
2017-10-01
Glucagon-like peptide-1 (GLP-1) receptor agonists are indicated for the treatment of Type 2 diabetes and obesity, but can cause nausea and emesis in some patients. GLP-1 receptors are distributed widely in the brain, where they contribute to mechanisms of emesis, reduced appetite and aversion, but it is not known if these centrally located receptors also contribute to a modulation of gastric slow wave activity, which is linked causally to nausea. Our aim was to investigate the potential of the GLP-1 receptor agonist, exendin-4, administered into the 3rd ventricle to modulate emesis, feeding and gastric slow wave activity. Thermoregulation and cardiovascular parameters were also monitored, as they are disturbed during nausea. Ferrets were used as common laboratory rodents do not have an emetic reflex. A guide cannula was implanted into the 3rd ventricle for delivering a previously established dose of exendin-4 (10nmol), which had been shown to induce emesis and behaviours indicative of 'nausea'. Radiotelemetry recorded gastric myoelectric activity (GMA; slow waves), blood pressure and heart rate variability (HRV), and core temperature; food intake and behaviour were also assessed. Exendin-4 (10nmol, i.c.v.) decreased the dominant frequency of GMA, with an associated increase in the percentage of bradygastric power (lasting ~4h). Food intake was inhibited in all animals, with 63% exhibiting emesis. Exendin-4 also increased blood pressure (lasting ~24h) and heart rate (lasting ~7h), decreased HRV (lasting ~24h), and caused transient hyperthermia. None of the above parameters were emesis-dependent. The present study shows for the first time that gastric slow waves may be modulated by GLP-1 receptors in the brain through mechanisms that appear independent from emesis. Taken together with a reduction in HRV, the findings are consistent with changes associated with the occurrence of nausea in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.
Godin, Oleg A.
2015-04-01
Much like light and sound, acoustic-gravity waves in inhomogeneous atmosphere often have a caustic or caustics, where the ray theory predicts unphysical, divergent values of the wave amplitude and needs to be modified. Increase of the wave magnitude in the vicinity of a caustic makes such vicinities of primary interest in a number of problems, where a signal needs to be separated from a background noise. The value of wave focusing near caustics should be carefully quantified in order to evaluate possible nonlinearities promoted by the focusing. Physical understanding of the wave field in the vicinity of a caustic is also important for understanding of the wave reflection from and transmission (tunneling) through the caustic. To our knowledge, in contrast to caustics of acoustic, electromagnetic, and seismic waves as well as gravity waves in incompressible fluids, asymptotics of acoustic-gravity waves in the vicinity of a caustic have never been studied systematically. In this paper, we fill this gap. Atmospheric waves are considered as linear acoustic-gravity waves in a neutral, horizontally stratified, moving ideal gas of variable composition. Air temperature and wind velocity are assumed to be gradually varying functions of height, and slowness of these variations determines the large parameter of the problem. The scale height of the atmosphere can be large or small compared to the vertical wavelength. It is found that the uniform asymptotics of the wave field in the presence of a simple caustic can be expressed in terms of the Airy function and its derivative. As for the acoustic waves, the argument of the Airy function is expressed in terms of the eikonal calculated in the ray, or WKB, approximation. The geometrical, or Berry, phase, which arises in the consistent WKB approximation for acoustic-gravity waves, plays an important role in the caustic asymptotics. In the uniform asymptotics, the terms with the Airy function and its derivative are weighted by cosine
Directory of Open Access Journals (Sweden)
Bessbousse H.
2013-04-01
Full Text Available Track-etched functionalized nanoporous β-PVDF membrane electrodes, or functionalized membrane electrodes (FMEs, are electrodes made from track-etched, poly(acrylic acid (PAA functionalized nanoporous β-poly(vinylidene fluoride (β-PVDF membranes with thin porous Au films sputtered on each side as electrodes. To form the β-PVDF nanoporous membranes, β-PVDF films are irradiated by swift heavy ions. After irradiation, radical tracks are stable in the membranes. Chemical etching removes some of the radical tracks revealing nanopores. Radicals, remaining in the pores, initiate radio grafting of PAA from the pore walls of the nanoporous β-PVDF. PAA is a cation exchange polymer that adsorbs metal ions, such as Pb2+, from aqueous solutions thus concentrating the ions into the membrane. After a calibrated time the FME is transferred to an electrochemical cell for square-wave anodic stripping voltammetry analysis.
Characteristic Evolution and Matching.
Winicour, Jeffrey
2012-01-01
I review the development of numerical evolution codes for general relativity based upon the characteristic initial-value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D-axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black-hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black-hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.
Impedance Matching of Tapered Slot Antenna using a Dielectric Transformer
Simons, R. N.; Lee, R. Q.
1998-01-01
A new impedance matching technique for tapered slot antennas using a dielectric transformer is presented. The technique is demonstrated by measuring the input impedance, Voltage Standing Wave Ratio (VSWR) and the gain of a Vivaldi antenna (VA). Measured results at Ka-Band frequencies are presented and discussed.
Effect of skew angle on second harmonic guided wave measurement in composite plates
Cho, Hwanjeong; Choi, Sungho; Lissenden, Cliff J.
2017-02-01
Waves propagating in anisotropic media are subject to skewing effects due to the media having directional wave speed dependence, which is characterized by slowness curves. Likewise, the generation of second harmonics is sensitive to micro-scale damage that is generally not detectable from linear features of ultrasonic waves. Here, the effect of skew angle on second harmonic guided wave measurement in a transversely isotropic lamina and a quasi-isotropic laminate are numerically studied. The strain energy density function for a nonlinear transversely isotropic material is formulated in terms of the Green-Lagrange strain invariants. The guided wave mode pairs for cumulative second harmonic generation in the plate are selected in accordance with the internal resonance criteria - i.e., phase matching and non-zero power flux. Moreover, the skew angle dispersion curves for the mode pairs are obtained from the semi-analytical finite element method using the derivative of the slowness curve. The skew angles of the primary and secondary wave modes are calculated and wave propagation simulations are carried out using COMSOL. Numerical simulations revealed that the effect of skew angle mismatch can be significant for second harmonic generation in anisotropic media. The importance of skew angle matching on cumulative second harmonic generation is emphasized and the accompanying issue of the selection of internally resonant mode pairs for both a unidirectional transversely isotropic lamina and a quasi-isotropic laminate is demonstrated.
Diffraction of electromagnetic waves by a two-dimensional periodic waveguide-dielectric array
Krekhtunov, V. M.; Tiulin, V. A.
1983-02-01
An analysis is presented of electromagnetic-wave diffraction by a two-dimensional periodic waveguide array covered by several layers of an inhomogeneous dielectric. For the case of quasi-periodic excitation of the array, the solution is obtained by the method of projection field matching in planes of junctions of longitudinally homogeneous regions. An orthonormal system of eigenvector functions of the transversely inhomogeneous Floquet channel is used as the basis in the two-dimensional periodic dielectric structure. The effectiveness of the proposed algorithm is demonstrated by a calculation of the coefficient of reflection of an incident wave from the aperture of an array of circular waveguides, matched with free space via stepwise dielectric rods. It is shown that the use of stepwise dielectric rods for the matching of waveguide antenna arrays is more effective than the use of dielectric cylinders jutting from the waveguides.
DEFF Research Database (Denmark)
Ljungberg, M.P.; Mortensen, Jens Jørgen; Pettersson, L.G.M.
2011-01-01
We describe the implementation of K-shell core level spectroscopies (X-ray absorption (XAS), X-ray emission (XES), and X-ray photoemission (XPS)) in the real-space-grid-based Projector Augmented Wave (PAW) GPAW code. The implementation for XAS is based on the Haydock recursion method avoiding...... computation of unoccupied states. The absolute energy scale is computed with the Delta Kohn–Sham method which is possible using specific PAW setups for the core-hole states. We show computed spectra for selected test cases (gas phase H2O and bulk diamond) and discuss the dependence on grid spacing and box...
El-sadr, W
1998-01-01
In this article, a physician working at Harlem Hospital in New York City describes how she awaited her Friday clinic with trepidation 10 years ago but now awaits it with eagerness inspired by her patients. To illustrate this phenomenon, she introduces several of her patients. First is Mary Ann who has multiple health problems compounded by AIDS and never misses a single dose of her medications, although the list of drugs she takes extends to two single-spaced pages. Next is Rochelle, a 36-year-old grandmother who transformed herself from a homeless drug addict when she learned she had AIDS. Then there is Jackie, whose fear sparked such irrational behavior that she caused commotions when she was in the waiting room. Jackie had to put AIDS treatment on hold to combat multiple drug-resistant tuberculosis yet she never missed a dose of medication. Another patient is Gardenia, who blames her young son's death not on AIDS but on his medication and who always has an excuse for not taking her medication. Lester has been drug-free for 102 days and asks tough, intelligent questions about the efficacy of his proposed treatment. Hermine arrives with a notebook stuffed with clippings and information she has gathered from a variety of sources because she is afraid of missing out on the newest magic drug. These patients are similar to other HIV/AIDS patients in that they encounter the same pain, frailties, and doubts, but they are individually distinct in the way that HIV/AIDS has transformed their lives and given them the courage to face daunting odds. This courage should be matched by a commitment on the part of physicians to understand current treatments and address key questions about treatment effectiveness.
Nonstationary distributions of wave intensities in wave turbulence
Choi, Yeontaek; Jo, Sanggyu; Kwon, Young-Sam; Nazarenko, Sergey
2017-09-01
We obtain a general solution for the probability density function (PDF) of wave intensities in non-stationary wave turbulence. The solution is expressed in terms of the initial PDF and the wave action spectrum satisfying the wave-kinetic equation. We establish that, in the absence of wave breaking, the wave statistics converge to a Gaussian distribution in forced-dissipated wave systems while approaching a steady state. Also, we find that in non-stationary systems, if the statistic is Gaussian initially, it will remain Gaussian for all time. Generally, if the statistic is not initially Gaussian, it will remain non-Gaussian over the characteristic nonlinear evolution time of the wave spectrum. In freely decaying wave turbulence, substantial deviations from Gaussianity may persist infinitely long.
Pitch matching psychometrics in electric acoustic stimulation.
Baumann, Uwe; Rader, Tobias; Helbig, Silke; Bahmer, Andreas
2011-01-01
Combined electric-acoustic stimulation (EAS) is a therapeutic option for patients with severe to profound mid- and high-frequency hearing loss while low-frequency hearing is mostly unaffected. The present study investigates bimodal pitch matching in EAS users as a function of the angular placement of electrodes. Results are compared with data obtained from previous pitch matching studies. Knowledge of electric and acoustic pitch mapping may be important for effective fitting to control the frequency range of acoustic and electric processing. Pitch adjustment experiments were conducted in eight subjects with residual hearing in the opposite ear as well as in the implanted ear. Four subjects received a standard 31.5-mm electrode array and four subjects received the shorter, more flexible 24-mm FLEX electrode array (PULSARCI100 or SONATATI100 stimulator, MED-EL, Innsbruck, Austria). The subjects' task was to listen to single-electrode stimuli presented at a fixed rate (800 pulses per second) via the cochlear implant and to adjust the frequency of the acoustic stimulus until the perceived pitch matched the perception of the electrically conveyed stimulus. Two to four of the most apical electrodes were tested depending on the range of the individual's residual hearing. Postoperative x rays (modified Stenver's view) were analyzed to compare individual pitch matching data in terms of the electrode arrays' insertion angle. The average mean frequency match for the most apical electrode 1 in EAS subjects implanted with the FLEX array was 583 Hz, while for the two subjects with a deep insertion of the 31.5-mm standard electrode array, the matches were 128 and 223 Hz. Because the residual hearing in the EAS subgroup was rather limited in the high-frequency range, a limited number of basal electrodes were assessed to determine the slope of the electric place/pitch function. A considerable variation in terms of the individual pitch function was observed. The slope of the pitch
History Matching: Towards Geologically Reasonable Models
DEFF Research Database (Denmark)
Melnikova, Yulia; Cordua, Knud Skou; Mosegaard, Klaus
that measures similarity between statistics of a training image and statistics of any smooth model is introduced and its analytical gradient is computed. This allows us to apply any gradientbased method to history matching problem and guide a solution until it satisfies both production data and complexity......This work focuses on the development of a new method for history matching problem that through a deterministic search finds a geologically feasible solution. Complex geology is taken into account evaluating multiple point statistics from earth model prototypes - training images. Further a function...
DEFF Research Database (Denmark)
Jensen, J.; Houmann, Jens Christian Gylden; Bjerrum Møller, Hans
1975-01-01
The energies of spin waves propagating in the c direction of Tb have been studied by inelastic neutron scattering, as a function of a magnetic field applied along the easy and hard directions in the basal plane, and as a function of temperature. From a general spin Hamiltonian, consistent...... with the symmetry, we deduce the dispersion relation for the spin waves in a basal-plane ferromagnet. This phenomenological spin-wave theory accounts for the observed behavior of the magnon energies in Tb. The two q⃗-dependent Bogoliubov components of the magnon energies are derived from the experimental results...
Skarpalezos, Loukas; Argyrakis, Panos; Vikhrenko, Vyacheslav S
2014-05-01
We investigate the self-intermediate scattering function (SISF) in a three-dimensional (3D) cubic lattice fluid (interacting lattice gas) with attractive nearest-neighbor interparticle interactions at a temperature slightly above the critical one by means of Monte Carlo simulations. A special representation of SISF as an exponent of the mean tracer diffusion coefficient multiplied by the geometrical factor and time is considered to highlight memory effects that are included in time and wave-vector dependence of the diffusion coefficient. An analytical expression for the diffusion coefficient is suggested to reproduce the simulation data. It is shown that the particles' mean-square displacement is equal to the time integral of the diffusion coefficient. We make a comparison with the previously considered 2D system on a square lattice. The main difference with the two-dimensional case is that the time dependence of particular characteristics of the tracer diffusion coefficient in the 3D case cannot be described by exponentially decreasing functions, but requires using stretched exponentials with rather small values of exponents, of the order of 0.2. The hydrodynamic values of the tracer diffusion coefficient (in the limit of large times and small wave vectors) defined through SIFS simulation results agree well with the results of its direct determination by the mean-square displacement of the particles in the entire range of concentrations and temperatures.
Nakano, Hiroshi; Yamamoto, Takeshi; Kato, Shigeki
2010-01-28
We first describe a wave-function based formalism of polarizable charge model by starting from the Hartree product ansatz for the total wave function and making the second-order expansion of individual molecular energies with the use of partial charge operators. The resulting model is shown to be formally equivalent to the charge response kernel model that starts from the linear-response approximation to partial charges, and also closely related to a family of fluctuating charge models that are based on the electronegativity equalization principle. We then apply the above model to a systematic comparison of polarization effects on qualitatively different liquids, namely, protic solvents (water and methanol), an aprotic polar solvent (acetonitrile), and imidazolium-based ionic liquids. Electronic polarization is known to decelerate molecular motions in conventional solvents while it accelerates them in ionic liquids. To obtain more insights into these phenomena, we consider an effective decomposition of total polarization energy into molecular contributions, and show that their statistical distribution is well-correlated with the acceleration/deceleration of molecular motions. In addition, we perform effective nonpolarizable simulations based on mean polarized charges, and compare them with fully polarizable simulations. The result shows that the former can reproduce structural properties of conventional solvents rather accurately, while they fail qualitatively to reproduce acceleration of molecular motions in ionic liquids.