Ultra-compact Higher-Order-Mode Pass Filter in a Silicon Waveguide
DEFF Research Database (Denmark)
Guan, Xiaowei; Frandsen, Lars Hagedorn; Ding, Yunhong
2015-01-01
An 3.7 μm long higher-order-mode pass filter with an extinction ratio larger than 20 dB is demonstrated in a 1D corrugated silicon multimode waveguide......An 3.7 μm long higher-order-mode pass filter with an extinction ratio larger than 20 dB is demonstrated in a 1D corrugated silicon multimode waveguide...
Thermal considerations in the cryogenic regime for the BNL double ridge higher order mode waveguide
Directory of Open Access Journals (Sweden)
Dhananjay K. Ravikumar
2017-09-01
Full Text Available Brookhaven National Laboratory (BNL has proposed to build an electron ion collider (EIC as an upgrade to the existing Relativistic Heavy Ion Collider (RHIC. A part of the new design is to use superconducting radio frequency (SRF cavities for acceleration, which sit in a bath of superfluid helium at a temperature of 2 K. SRF cavities designed for the BNL EIC create a standing electromagnetic wave, oscillating at a fundamental frequency of 647 MHz. Interaction of the charged particle beam with the EM field in the cavity creates higher order modes (HOM of oscillation which have adverse effects on the beam when allowed to propagate down the beam tube. HOM waveguides are thus designed to remove this excess energy which is then damped at room temperature. As a result, these waveguides provide a direct thermal link between room temperature and the superconducting cavities adding a static thermal load. The EM wave propagating through the warmer sections of the waveguide creates an additional dynamic thermal load. This study calculates these thermal loads, concluding that the dynamic load is small in comparison to the static load. Temperature distributions are mapped on the waveguide and the number of heat intercepts required to efficiently manage thermal loads have been determined. In addition, a thermal radiation study has been performed and it is found that this contribution is around three orders of magnitude smaller than the static conduction and dynamic loads.
Thermal considerations in the cryogenic regime for the BNL double ridge higher order mode waveguide
Ravikumar, Dhananjay K.; Than, Yatming; Xu, Wencan; Longtin, Jon
2017-09-01
Brookhaven National Laboratory (BNL) has proposed to build an electron ion collider (EIC) as an upgrade to the existing Relativistic Heavy Ion Collider (RHIC). A part of the new design is to use superconducting radio frequency (SRF) cavities for acceleration, which sit in a bath of superfluid helium at a temperature of 2 K. SRF cavities designed for the BNL EIC create a standing electromagnetic wave, oscillating at a fundamental frequency of 647 MHz. Interaction of the charged particle beam with the EM field in the cavity creates higher order modes (HOM) of oscillation which have adverse effects on the beam when allowed to propagate down the beam tube. HOM waveguides are thus designed to remove this excess energy which is then damped at room temperature. As a result, these waveguides provide a direct thermal link between room temperature and the superconducting cavities adding a static thermal load. The EM wave propagating through the warmer sections of the waveguide creates an additional dynamic thermal load. This study calculates these thermal loads, concluding that the dynamic load is small in comparison to the static load. Temperature distributions are mapped on the waveguide and the number of heat intercepts required to efficiently manage thermal loads have been determined. In addition, a thermal radiation study has been performed and it is found that this contribution is around three orders of magnitude smaller than the static conduction and dynamic loads.
DEFF Research Database (Denmark)
Guan, Xiaowei; Ding, Yunhong; Frandsen, Lars Hagedorn
2015-01-01
. Consequently, light on the lower order mode is prohibited to pass through the filter, while light on a higher order mode can be converted to a Bloch mode in the photonic crystal and pass through the filter with low insertion loss. As an example, we fabricate a similar to 15-mu m-long first-order-mode pass......An ultra-compact and broadband higher order-mode pass filter in a 1D photonic crystal silicon waveguide is proposed and experimentally demonstrated. The photonic crystal is designed for the lower order mode to work in the photonic band gap, while the higher order mode is located in the air band...... filter that filters out the fundamental mode and provides a measured insertion loss of similar to 1.8 dB for the first-order-mode pass signals. The extinction ratio is measured to be around 50 dB (with a variation of +/- 10 dB due to the detection limitation of the measurement setup) in the measured...
DEFF Research Database (Denmark)
Ernst, Erik
2003-01-01
This paper introduces the notion of higher-order inheritance hierarchies. They are useful because they provide well-known benefits of object-orientation at the level of entire hierarchies-benefits which are not available with current approaches. Three facets must be adressed: First, it must...
DEFF Research Database (Denmark)
Israelsen, Stine Møller
This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others....... The research presented in this thesis falls in three parts. In the first part, a first time demonstration of the break of the azimuthal symmetry of the Bessel-like LP0X modes is presented. This effect, known as the bowtie effect, causes the mode to have an azimuthal dependence as well as a quasi......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...
Higher-Order Program Generation
DEFF Research Database (Denmark)
Rhiger, Morten
This dissertation addresses the challenges of embedding programming languages, specializing generic programs to specific parameters, and generating specialized instances of programs directly as executable code. Our main tools are higher-order programming techniques and automatic program generation...... infrastructure of higher-order functions, types, and modules. Furthermore, it has been observed that embedded programs can be restricted to those having simple types using a technique called ``phantom types''. We prove, using an idealized higher-order language, that such an embedding is sound (i.e., when all...... to the disproportion between general programs that can be executed in several contexts and their specialized counterparts that can be executed efficiently. However, stand-alone partial evaluation is usually too costly when a program must be specialized at run time. We introduce a collection of byte-code combinators...
Nonlocal higher order evolution equations
Rossi, Julio D.
2010-06-01
In this article, we study the asymptotic behaviour of solutions to the nonlocal operator ut(x, t)1/4(-1)n-1 (J*Id -1)n (u(x, t)), x ∈ ℝN, which is the nonlocal analogous to the higher order local evolution equation vt(-1)n-1(Δ)nv. We prove that the solutions of the nonlocal problem converge to the solution of the higher order problem with the right-hand side given by powers of the Laplacian when the kernel J is rescaled in an appropriate way. Moreover, we prove that solutions to both equations have the same asymptotic decay rate as t goes to infinity. © 2010 Taylor & Francis.
Resilience and Higher Order Thinking
Directory of Open Access Journals (Sweden)
Ioan Fazey
2010-09-01
Full Text Available To appreciate, understand, and tackle chronic global social and environmental problems, greater appreciation of the importance of higher order thinking is required. Such thinking includes personal epistemological beliefs (PEBs, i.e., the beliefs people hold about the nature of knowledge and how something is known. These beliefs have profound implications for the way individuals relate to each other and the world, such as how people understand complex social-ecological systems. Resilience thinking is an approach to environmental stewardship that includes a number of interrelated concepts and has strong foundations in systemic ways of thinking. This paper (1 summarizes a review of educational psychology literature on PEBs, (2 explains why resilience thinking has potential to facilitate development of more sophisticated PEBs, (3 describes an example of a module designed to teach resilience thinking to undergraduate students in ways conducive to influencing PEBs, and (4 discusses a pilot study that evaluates the module's impact. Theoretical and preliminary evidence from the pilot evaluation suggests that resilience thinking which is underpinned by systems thinking has considerable potential to influence the development of more sophisticated PEBs. To be effective, however, careful consideration of how resilience thinking is taught is required. Finding ways to encourage students to take greater responsibility for their own learning and ensuring close alignment between assessment and desired learning outcomes are particularly important.
Second-order virial expansion for an atomic gas in a harmonic waveguide
Kristensen, Tom; Leyronas, Xavier; Pricoupenko, Ludovic
2016-06-01
The virial expansion for cold two-component Fermi and Bose atomic gases is considered in the presence of a waveguide and in the vicinity of a Feshbach resonance. The interaction between atoms and the coupling with the Feshbach molecules is modeled using a quantitative separable two-channel model. The scattering phase shift in an atomic waveguide is defined. This permits us to extend the Beth-Uhlenbeck formula for the second-order virial coefficient to this inhomogeneous case.
Higher order mode optical fiber Raman amplifiers
DEFF Research Database (Denmark)
Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.
2016-01-01
We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....
Challenges in higher order mode Raman amplifiers
DEFF Research Database (Denmark)
Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk
2015-01-01
A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...
Formation of higher-band dark gap solitons in one dimensional waveguide arrays.
Dong, Rong; Rüter, Christian E; Song, Daohong; Xu, Jingjun; Kip, Detlef
2010-12-20
We experimentally observe the formation of spatial dark gap solitons in higher bands in one-dimensional waveguide arrays possessing a saturable defocusing nonlinearity. By using the prism-coupler scheme, pure Floquet-Bloch modes of higher bands are excited and dark gap solitons are formed due to the counteraction of normal diffraction and the defocusing nature of the photovoltaic nonlinearity. The modulation of refractive index induced by the soliton formation is demonstrated by the guidance of a low-power probe beam in the waveguide array sample. Additionally, the phase structure of dark solitons formed in the second band is discussed.
Modal theory of slow light enhanced third-order nonlinear effects in photonic crystal waveguides.
Chen, Tao; Sun, Junqiang; Li, Linsen
2012-08-27
In this paper, we derive the couple-mode equations for third-order nonlinear effects in photonic crystal waveguides by employing the modal theory. These nonlinear interactions include self-phase modulation, cross-phase modulation and degenerate four-wave mixing. The equations similar to that in nonlinear fiber optics could be expanded and applied for third-order nonlinear processes in other periodic waveguides. Based on the equations, we systematically analyze the group-velocity dispersion, optical propagation loss, effective interaction area, slow light enhanced factor and phase mismatch for a slow light engineered silicon photonic crystal waveguide. Considering the two-photon and free-carrier absorptions, the wavelength conversion efficiencies in two low-dispersion regions are numerically simulated by utilizing finite difference method. Finally, we investigate the influence of slow light enhanced multiple four-wave-mixing process on the conversion efficiency.
DEFF Research Database (Denmark)
Appel, Claus; van Oostrom, Vincent; Simonsen, Jakob Grue
2010-01-01
We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. We show that for the particular format of simply typed applicative term rewriting syst...
Higher-order techniques in computational electromagnetics
Graglia, Roberto D
2016-01-01
Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.
Order-sorted Algebraic Specifications with Higher-order Functions
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth
1995-01-01
This paper gives a proposal for how order-sorted algebraic specification languages can be extended with higher-order functions. The approach taken is a generalisation to the order-sorted case of an approach given by Mller, Tarlecki and Wirsing for the many-sorted case. The main idea in the proposal...
Static Complexity Analysis of Higher Order Programs
DEFF Research Database (Denmark)
Avery, James Emil; Kristiansen, Lars; Moyen, Jean-Yves
2009-01-01
The overall goal of the research presented in this paper is to find^Mautomatic methods for static complexity analysis of higher order^Mprograms.......The overall goal of the research presented in this paper is to find^Mautomatic methods for static complexity analysis of higher order^Mprograms....
HIGHER ORDER THINKING IN TEACHING GRAMMAR
Directory of Open Access Journals (Sweden)
Citra Dewi
2017-04-01
Full Text Available The aim of this paper discussed about how to enhance students’ higher order thinking that should be done by teacher in teaching grammar. Usually teaching grammar was boring and has the same way to learn like change the pattern of sentence into positive, negative and introgative while the students’ need more various way to develop their thinking. The outcome of students’ competence in grammar sometimes not sufficient enough when the students’ occured some test international standart like Test of English Foreign Language, International English Language Testing. Whereas in TOEFL test it needed higher order thinking answer, so teacher should develop students’ higher order thingking in daily teaching grammar in order to make the students’ enhance their thinking are higher. The method was used in this paper by using field study based on the experience of teaching grammar. It can be shown by students’ toefl score was less in stucture and written expression. The result of this paper was after teacher gave some treatments to enhance students’ higher order thinking in teaching grammar, the students’ toefl scores are sufficient enough as a part of stucture and written expression. It can concluded that it needed some strategies to enhancce students higher order thinking by teaching grammar it can make students’ higher toefl score. Teachers should be creative and inovative to teach the students’ started from giving the students’ question or test in teaching grammar.
Higher-Order Minimal Functional Graphs
DEFF Research Database (Denmark)
Jones, Neil D; Rosendahl, Mads
1994-01-01
We present a minimal function graph semantics for a higher-order functional language with applicative evaluation order. The semantics captures the intermediate calls performed during the evaluation of a program. This information may be used in abstract interpretation as a basis for proving...
Electric Field-Induced Second Order Nonlinear Optical Effects in Silicon Waveguides
Timurdogan, E; Watts, M R
2016-01-01
The demand for nonlinear effects within a silicon platform to support photonic circuits requiring phase-only modulation, frequency doubling, and/or difference frequency generation, is becoming increasingly clear. However, the symmetry of the silicon crystal inhibits second order optical nonlinear susceptibility, $\\chi^{(2)}$. Here, we show that the crystalline symmetry is broken when a DC field is present, inducing a $\\chi^{(2)}$ in a silicon waveguide that is proportional to the large $\\chi^{(3)}$ of silicon. First, Mach-Zehnder interferometers using the DC Kerr effect optical phase shifters in silicon ridge waveguides with p-i-n junctions are demonstrated with a $V_{\\pi}L$ of $2.4Vcm$ in telecom bands $({\\lambda}_{\\omega}=1.58{\\mu}m)$ without requiring to dope the silicon core. Second, the pump and second harmonic modes in silicon ridge waveguides are quasi-phase matched when the magnitude, spatial distribution of the DC field and $\\chi^{(2)}$ are controlled with p-i-n junctions. Using these waveguides, sec...
Simple Correctors for Elimination of High-Order Modes in Corrugated Waveguide Transmission Lines.
Kowalski, Elizabeth J; Shapiro, Michael A; Temkin, Richard J
2014-01-01
When using overmoded corrugated waveguide transmission lines for high power applications, it is necessary to control the mode content of the system. Ideally, overmoded corrugated transmission lines operate in the fundamental HE11 mode and provide low losses for long distances. Unwanted higher order modes (HOMs), particularly LP11 and HE12, are often excited in the experimental systems due to practical misalignments in the transmission line system. This paper discusses how the unwanted modes propagate along with the fundamental mode in the transmission line system by formulating an equation that relates the center of power offset and angle of propagation of a beam (for the HE11 and LP11 modes) or the waist size and phase front radius of curvature of a beam (for the HE11 and HE12 modes). By introducing two miter bend correctors into the transmission system-miter bends that have slightly angled or ellipsoidal mirrors-the HOMs can be precisely manipulated in the system. This technique can be used to eliminate small quantities of unwanted modes, thereby creating a nearly pure fundamental mode beam with minimal losses. Examples of these applications are calculated and show the theoretical conversion of up to 10% HOM content into the fundamental HE11 mode with minimal losses.
Higher Order Thinking in the Dance Studio
Moffett, Ann-Thomas
2012-01-01
The author identifies higher order thinking as an essential component of dance training for students of all ages and abilities. Weaving together insights from interviews with experts in the field of dance education with practical pedagogical applications within an Improvisation and Composition class for talented and gifted youth, this article…
Extending CASL with Higher-order Functions
DEFF Research Database (Denmark)
Haxthausen, Anne; Krieg-Brückner, Bernd; Mossakowski, Till
1998-01-01
We present a proposal for the design of the higher-order extension of CASL. For each design step, we have tried to find the best of several possible alternatives, give a motivation for the preferred alternative and argue why the other alternatives are not taken. This note discusses function space...
Higher Order and Fractional Diffusive Equations
Directory of Open Access Journals (Sweden)
D. Assante
2015-07-01
Full Text Available We discuss the solution of various generalized forms of the Heat Equation, by means of different tools ranging from the use of Hermite-Kampé de Fériet polynomials of higher and fractional order to operational techniques. We show that these methods are useful to obtain either numerical or analytical solutions.
Higher-Order Resonances in Dynamical Systems
Tuwankotta, J.M.
2002-01-01
This thesis is a collection of studies on higher-order resonances in an important class of dynamical systems called coupled oscillators systems. After giving an overview of the mathematical background, we start in Chapter 1 by presenting a study on resonances in two degrees of freedom, autonomous,
Higher-Order Components for Grid Programming
Dünnweber, Jan
2009-01-01
Higher-Order Components were developed within the CoreGRID European Network of Excellence and have become an optional extension of the popular Globus middleware. This book provides the reader with hands-on experience, describing a collection of example applications from various fields of science and engineering, including biology and physics.
Frontiers of higher order fuzzy sets
Tahayori, Hooman
2015-01-01
Frontiers of Higher Order Fuzzy Sets, strives to improve the theoretical aspects of general and Interval Type-2 fuzzy sets and provides a unified representation theorem for higher order fuzzy sets. Moreover, the book elaborates on the concept of gradual elements and their integration with the higher order fuzzy sets. This book also introduces new frameworks for information granulation based on general T2FSs, IT2FSs, Gradual elements, Shadowed sets and rough sets. In particular, the properties and characteristics of the new proposed frameworks are studied. Such new frameworks are shown to be more capable to be exploited in real applications. Higher order fuzzy sets that are the result of the integration of general T2FSs, IT2FSs, gradual elements, shadowed sets and rough sets will be shown to be suitable to be applied in the fields of bioinformatics, business, management, ambient intelligence, medicine, cloud computing and smart grids. Presents new variations of fuzzy set frameworks and new areas of applicabili...
Higher order cumulants in colorless partonic plasma
Energy Technology Data Exchange (ETDEWEB)
Cherif, S. [Sciences and Technologies Department, University of Ghardaia, Ghardaia, Algiers (Algeria); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ahmed, M. A. A. [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Department of Physics, Taiz University in Turba, Taiz (Yemen); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ladrem, M., E-mail: mladrem@yahoo.fr [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria)
2016-06-10
Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.
Energy Technology Data Exchange (ETDEWEB)
Wang, Guanghui, E-mail: gsnuwgh@163.com; Zhang, Weifeng; Lu, Jiahui; Zhao, Huijun
2016-08-12
We analytically study dispersion properties and optical gradient forces of different-order transverse magnetic (TM) modes in two coupled hyperbolic metamaterial waveguides (HMMWs). According to Maxwell's equations, we obtain the dispersion relation of symmetric and antisymmetric modes, and calculate optical gradient forces of different-order modes by using Maxwell stress tensor. Numerical results show that the dispersion properties are dependent on the filling ratio, and the optical gradient forces of high-order TM modes are larger than the fundamental mode when the gap between two HMMWs is very narrow, but they weaken much faster than the case of low-order TM modes with the gap width increasing. In addition, the effects of the dielectric surrounding of waveguides on the coupling effect and optical gradient force are clarified. These properties offer an avenue for various optomechanical applications in optical sensors and actuators. - Highlights: • The dependence of dispersion properties in hyperbolic metamaterials on the filling ratio is analyzed. • It is possible that the optical gradient forces of high-order modes are larger than the fundamental mode. • Optical gradient forces of high-order modes weaken much faster than the case of low-order modes. • The influence of the dielectric surrounding on the coupling effect and optical gradient force are clarified.
Higher-order aberrations and anisometropia.
Hartwig, Andreas; Atchison, David A; Radhakrishnan, Hema
2013-01-01
Myopia incidence is increasing around the world. Myopization is considered to be caused by a variety of factors. One consideration is whether higher-order aberrations (HOA) influence myopization. More knowledge of optics in anisometropic eyes might give further insight into the development of refractive error. To analyze the possible influence of HOA on refractive error development, we compared HOA between anisometropes and isometropes. We analyzed HOA up to the 4th order for both eyes of 20 anisometropes (mean age: 43 ± 17 years) and 20 isometropes (mean age: 33 ± 17 years). HOA were measured with the Shack-Hartman i.Profiler (Carl Zeiss, Germany) and were recalculated for a 4 mm pupil. Mean spherical equivalent (MSE) was based on the subjective refraction. Anisometropia was defined as ≥1 D interocular difference in MSE. The mean absolute differences between right and left eyes in spherical equivalent were 0.28 ± 0.21 D in the isometropic group and 2.81 ± 2.04 D in the anisometropic group. Interocular differences in HOA were compared with the interocular difference in MSE using correlations. For isometropes oblique trefoil, vertical coma, horizontal coma and spherical aberration showed significant correlations between the two eyes. In anisometropes, all analyzed higher-order aberrations correlated significantly between the two eyes except oblique secondary astigmatism and secondary astigmatism. When analyzing anisometropes and isometropes separately, no significant correlations were found between interocular differences of higher-order aberrations and MSE. For isometropes and anisometropes combined, tetrafoil correlated significantly with MSE in left eyes. The present study could not show that interocular differences of higher-order aberrations increase with increasing interocular difference in MSE.
Sophisticated Thinking: Higher Order Thinking Skills
Elena Tikhonova; Natalia Kudinova
2015-01-01
The information-based society determines that the key factor to achieve success is the development of sophisticated thinking. That said, the thinking process cannot be just a mere imitation of cognitive work, since the digital age requires the authentic skills of working with a flow of information that is being constantly updated. This paper deals with the last stage of the study devoted to the development of sophisticated thinking. It focuses on the enhancement of higher order thinking sk...
Automatic code generator for higher order integrators
Mushtaq, Asif; Olaussen, Kåre
2014-05-01
Some explicit algorithms for higher order symplectic integration of a large class of Hamilton's equations have recently been discussed by Mushtaq et al. Here we present a Python program for automatic numerical implementation of these algorithms for a given Hamiltonian, both for double precision and multiprecision computations. We provide examples of how to use this program, and illustrate behavior of both the code generator and the generated solver module(s).
Directory of Open Access Journals (Sweden)
John W. Lewellen
2001-04-01
Full Text Available Traditional photocathode rf gun design is based around the use of TM_{0,1,0}-mode cavities. This is typically done in the interest of obtaining the highest possible gradient per unit supplied rf power and for historical reasons. In a multicell, aperture-coupled photoinjector, however, the gun as a whole is produced from strongly coupled cavities oscillating in a π mode. This design requires very careful preparation and tuning, as the field balance and resonant frequencies are easily disturbed. Side-coupled designs are often avoided because of the dipole modes introduced into the cavity fields. This paper proposes the use of a single higher-order mode rf cavity in order to generate the desired on-axis fields. It is shown that the field experienced by a beam in a higher-order mode rf gun is initially very similar to traditional 1.5- or 2.5-cell π-mode gun fields, and projected performance in terms of beam quality is also comparable. The new design has the advantages of much greater ease of fabrication, immunity from coupled-cell effects, and simpler tuning procedures. Because of the gun geometry, the possibility also exists for improved temperature stabilization and cooling for high duty-cycle applications.
Second-order optical nonlinearities in dilute melt proton exchange waveguides in z-cut LiNbO3
DEFF Research Database (Denmark)
Veng, Torben Erik; Skettrup, Torben; Pedersen, Kjeld
1996-01-01
Planar optical waveguides with different refractive indices are made in z-cut LiNbO3 with a dilute proton exchange method using a system of glycerol containing KHSO4 and lithium benzoate. The optical second-order susceptibilities of these waveguides are measured by detecting the 266 nm reflected .......013 at the 632.8 nm wavelength, whereas the susceptibilities are strongly reduced for larger index changes. (C) 1996 American Institute of Physics....
Higher order integral stark-type conjectures
Emmons, Caleb J.
2006-01-01
The Stark conjectures attempt to capture the leading terms at s=0 of the S-incomplete Artin L-functions attached to an abelian extension of number fields as the image under a regulator map of an evaluator built out of S-units. We introduce a new conjecture of Popescu, which extends Rubin's higher order of vanishing Stark-type conjecture by removing the hypothesis that S contains splitting primes. We prove that the evaluator attached to an extension K/k can be written as a linear combina...
Nonconservative higher-order hydrodynamic modulation instability
Kimmoun, O.; Hsu, H. C.; Kibler, B.; Chabchoub, A.
2017-08-01
The modulation instability (MI) is a universal mechanism that is responsible for the disintegration of weakly nonlinear narrow-banded wave fields and the emergence of localized extreme events in dispersive media. The instability dynamics is naturally triggered, when unstable energy sidebands located around the main energy peak are excited and then follow an exponential growth law. As a consequence of four wave mixing effect, these primary sidebands generate an infinite number of additional sidebands, forming a triangular sideband cascade. After saturation, it is expected that the system experiences a return to initial conditions followed by a spectral recurrence dynamics. Much complex nonlinear wave field motion is expected, when the secondary or successive sideband pair that is created is also located in the finite instability gain range around the main carrier frequency peak. This latter process is referred to as higher-order MI. We report a numerical and experimental study that confirms observation of higher-order MI dynamics in water waves. Furthermore, we show that the presence of weak dissipation may counterintuitively enhance wave focusing in the second recurrent cycle of wave amplification. The interdisciplinary weakly nonlinear approach in addressing the evolution of unstable nonlinear waves dynamics may find significant resonance in other nonlinear dispersive media in physics, such as optics, solids, superfluids, and plasma.
Theorem Proving In Higher Order Logics
Carreno, Victor A. (Editor); Munoz, Cesar A.; Tahar, Sofiene
2002-01-01
The TPHOLs International Conference serves as a venue for the presentation of work in theorem proving in higher-order logics and related areas in deduction, formal specification, software and hardware verification, and other applications. Fourteen papers were submitted to Track B (Work in Progress), which are included in this volume. Authors of Track B papers gave short introductory talks that were followed by an open poster session. The FCM 2002 Workshop aimed to bring together researchers working on the formalisation of continuous mathematics in theorem proving systems with those needing such libraries for their applications. Many of the major higher order theorem proving systems now have a formalisation of the real numbers and various levels of real analysis support. This work is of interest in a number of application areas, such as formal methods development for hardware and software application and computer supported mathematics. The FCM 2002 consisted of three papers, presented by their authors at the workshop venue, and one invited talk.
Single-arm double-mode double-order planar waveguide interferometric sensor.
Sarkisov, S S; Diggs, D E; Adamovsky, G; Curley, M J
2001-01-20
A sensor is described for which interference measurements of the phase delay between two propagating modes of different orders in a slab thin-film waveguide are used as the sensing technique. The basic building block of the sensor is a polymer film doped with an indicator dye such as Bromocresol Purple. The modes of two orders such as TM(0) and TM(1) are simultaneously excited in the light-guiding film with a focusing optics and a prism coupler. The modes are decoupled from the film and recombined to produce an interference pattern in the face of an output optical fiber. The sensitivity of the sensor to the ambient temperature change is 1.5 degrees C, and the sensitivity to NH(3) is 200 parts in 10(6) for one full oscillation of the signal.
Higher order corrections in perturbative quantum chromodynamics
Indian Academy of Sciences (India)
We present some techniques which have been developed recently or in the recent past to compute Feynman graphs beyond one-loop order. These techniques are useful to compute the three-loop splitting functions in QCD and to obtain the complete second order QED corrections to Bhabha scattering.
Higher order corrections in perturbative quantum chromodynamics
Indian Academy of Sciences (India)
to compute Feynman graphs beyond one-loop order. These techniques are useful to compute the three-loop splitting functions in QCD and to obtain the complete second order QED corrections to. Bhabha scattering. ..... ¾ into the following special functions [9] given by the hyper-geometric functions. ¾F½, ¿F¾, the Appell ...
Heavy quark threshold dynamics in higher order
Energy Technology Data Exchange (ETDEWEB)
Piclum, J.H.
2007-05-15
In this work we discuss an important building block for the next-to-next-to-next-to leading order corrections to the pair production of top quarks at threshold. Specifically, we explain the calculation of the third order strong corrections to the matching coefficient of the vector current in non-relativistic Quantum Chromodynamics and provide the result for the fermionic part, containing at least one loop of massless quarks. As a byproduct, we obtain the matching coefficients of the axial-vector, pseudo-scalar and scalar current at the same order. Furthermore, we calculate the three-loop corrections to the quark renormalisation constants in the on-shell scheme in the framework of dimensional regularisation and dimensional reduction. Finally, we compute the third order strong corrections to the chromomagnetic interaction in Heavy Quark Effective Theory. The calculational methods are discussed in detail and results for the master integrals are given. (orig.)
Higher order Hessian structures on manifolds
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
+ Xψ. D2F · Sϕ. (9). If Sϕ = Yϕ Zϕ, we write Rϕ(Xϕ,Yϕ,Zϕ) = Rϕ(Xϕ,Yϕ Zϕ) and similarly for Cϕ. 4. Third-order Hessian structures. Let K be a third-order Hessian structure on M (the case n = 3 of Definition 2.1). In what follows we state that the following lemma and the proof is easy and hence left to the reader. Lemma 4.1.
National Research Council Canada - National Science Library
Notaros, Branislav M; Ilic, Milan M; Djordjevic, Miroslav
2004-01-01
...), method of moments (MoM), and physical optics (PO). The simulations combine higher order geometrical modeling and higher order field/current modeling, which is referred to as double-higher-order modeling...
Higher Order Macro Coefficients in Periodic Homogenization
Energy Technology Data Exchange (ETDEWEB)
Conca, Carlos; San Martin, Jorge [Departamento de IngenierIa Matematica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile and Centro de Modelamiento Matematico, UMR 2071 CNRS-UChile, Casilla 170/3 - Correo 3, Santiago (Chile); Smaranda, Loredana [Department of Mathematics, Faculty of Mathematics and Computer Science, University of Pitesti, 110040 Pitesti, Str. Targu din Vale Nr.1, Arges (Romania); Vanninathan, Muthusamy, E-mail: cconca@dim.uchile.cl, E-mail: jorge@dim.uchile.cl, E-mail: smaranda@dim.uchile.cl, E-mail: vanni@math.tifrbng.res.in [TIFR-CAM, Post Bag 6503, GKVK Post, Bangalore - 560065 (India)
2011-09-15
A first set of macro coefficients known as the homogenized coefficients appear in the homogenization of PDE on periodic structures. If energy is increased or scale is decreased, these coefficients do not provide adequate approximation. Using Bloch decomposition, it is first realized that the above coefficients correspond to the lowest energy and the largest scale. This naturally paves the way to introduce other sets of macro coefficients corresponding to higher energies and lower scales which yield better approximation. The next task is to compare their properties with those of the homogenized coefficients. This article reviews these developments along with some new results yet to be published.
Systems with Higher-Order Modulation
Seimetz, Matthias
With the objective of reducing costs per information bit in optical communication networks, per fibre capacities and optical transparent transmission lengths have been stepped up by the introduction of new technology in recent years. The innovation of the erbium-doped fibre amplifier (EDFA) at the beginning of the nineties facilitated long distances to be bridged without electro-optical conversion. Wavelength division multiplexing (WDM) technology allowed a lot of wavelength channels to be simultaneously transmitted over one fibre and to be amplified by one EDFA with high bandwidth, offering a huge network capacity. At this time, the modulation format of choice was the simple "on-off keying" (OOK), and there was no need for increasing spectral efficiency. The internet traffic growth during the nineties required increasing transmission rates. In that context, the transmission impairments of the optical fibre had to be counteracted and the application of differential binary phased shift keying (DBPSK) became an issue, providing for a higher robustness against nonlinear effects [1]. Moreover, the transmission behaviour of binary intensity modulation was optimized by using alternative optical pulse shapes such as return to zero (RZ) and by employing schemes with auxiliary phase coding, such as optical duobinary, which exhibits a higher tolerance against chromatic dispersion (CD). The capacity-distance product was further enhanced by applying optical dispersion compensation, Raman amplification and advanced optical fibres, as well as through electronic means, such as forward error correction (FEC) and the adaptive compensation of CD and polarization mode dispersion (PMD).
Higher Order Continuous SI Engine Observers
DEFF Research Database (Denmark)
Vesterholm, Thomas; Hendricks, Elbert; Houbak, Niels
1992-01-01
A nonlinear compensator for the fuel film dynamics and a second order nonlinear observer for a spark ignition engine are presented in this paper. The compensator and observer are realized as continuous differential equations and an especially designed integration algorithm is used to integrate them...... in real time. Using these means, accurate steady state and transient air/fuel control can be obtained with excellent robustness properties. Some useful condition monitoring facilities are also available in the observer. The compensator and observer are based on a Mean Value Engine Model (MVEM) presented...... earlier. A MVEM is one which predicts the mean value of the engine states and internal variables over time scales which are large compared to the cyclic engine process....
Visualising higher order Brillouin zones with applications
Andrew, R. C.; Salagaram, T.; Chetty, N.
2017-05-01
A key concept in material science is the relationship between the Bravais lattice, the reciprocal lattice and the resulting Brillouin zones (BZ). These zones are often complicated shapes that are hard to construct and visualise without the use of sophisticated software, even by professional scientists. We have used a simple sorting algorithm to construct BZ of any order for a chosen Bravais lattice that is easy to implement in any scientific programming language. The resulting zones can then be visualised using freely available plotting software. This method has pedagogical value for upper-level undergraduate students since, along with other computational methods, it can be used to illustrate how constant-energy surfaces combine with these zones to create van Hove singularities in the density of states. In this paper we apply our algorithm along with the empirical pseudopotential method and the 2D equivalent of the tetrahedron method to show how they can be used in a simple software project to investigate this interaction for a 2D crystal. This project not only enhances students’ fundamental understanding of the principles involved but also improves transferable coding skills.
Concept Mapping for Higher Order Thinking
Directory of Open Access Journals (Sweden)
Susan Marie Zvacek
2013-02-01
Full Text Available Engineering education is facing a changing world in which how one thinks is becoming more important than what one thinks; that is, our course content is important but constantly changing and we need to help students learn how to think about that content.Today’s students have grown accustomed to immediate rewards, multi-channel stimuli, and rapid-fire communications. As a result, they are often impatient and suffer a lack of focus. When reflection is called for in the learning process - a time consuming practice - students may find it difficult to overcome the conflict between their typically speedy management of priorities and the focused, time-intensive thinking required to acquire a strong foundation of declarative knowledge.Therefore, the exploration of tools to facilitate the formation of deep knowledge structures is essential. One instructional strategy that shows promise is the use of concept mapping, a learning activity that requires students to explain their understanding of important ideas and the relationships among those ideas. This paper describes a pilot project to integrate concept mapping into a Mechanical Engineering Course and the preliminary results of that project.This project has been established within the Working Group of “Tools for Developing High Order Thinking Skills”, of the Portuguese Society for Engineering Education, in which the first author is the leader and the other two co-authors, are working group members
CLIC Waveguide Damped Accelerating Structure Studies
Dehler, M; Wuensch, Walter
1996-01-01
Studies of waveguide damped 30 GHz accelerating structures for multibunching in CLIC are described. Frequency discriminated damping using waveguides with a lowest cutoff frequency above the fundamental but below the higher order modes was considered. The wakefield behavior was investigated using time domain MAFIA computations over up to 20 cells and for frequencies up to 150 GHz. A configuration consisting of four T-cross-sectioned waveguides per cell reduces the transverse wake below 1% at typical CLIC bunch spacings.
Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil
2017-02-01
Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
Skinner-Rusk unified formalism for higher-order systems
Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso
2012-07-01
The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.
Conceptualizing and Assessing Higher-Order Thinking in Reading
Afflerbach, Peter; Cho, Byeong-Young; Kim, Jong-Yun
2015-01-01
Students engage in higher-order thinking as they read complex texts and perform complex reading-related tasks. However, the most consequential assessments, high-stakes tests, are currently limited in providing information about students' higher-order thinking. In this article, we describe higher-order thinking in relation to reading. We provide a…
Metasurface Waveguides Applied to Matched Feeds for Reflector Antennas
DEFF Research Database (Denmark)
Palvig, Michael Forum; Jorgensen, Erik; Meincke, Peter
2017-01-01
Waveguides with anisotropic surface impedance boundaries have been investigated for the purpose of matched feeds for offset reflectors. Matched feeds employ higher order waveguide modes to cancel out cross polarization introduced by the offset geometry. Since the higher order modes propagate at d...
Higher-Order Finite Element Solutions of Option Prices
DEFF Research Database (Denmark)
Raahauge, Peter
2004-01-01
Kinks and jumps in the payoff function of option contracts prevent an effectiveimplementation of higher-order numerical approximation methods. Moreover, thederivatives (the greeks) are not easily determined around such singularities, even withstandard lower-order methods. This paper suggests...
Lower Bounds for Higher-Order Convex Optimization
Agarwal, Naman; Hazan, Elad
2017-01-01
State-of-the-art methods in convex and non-convex optimization employ higher-order derivative information, either implicitly or explicitly. We explore the limitations of higher-order optimization and prove that even for convex optimization, a polynomial dependence on the approximation guarantee and higher-order smoothness parameters is necessary. As a special case, we show Nesterov's accelerated cubic regularization method to be nearly tight.
The Role of Formative Feedback in Promoting Higher Order ...
African Journals Online (AJOL)
DrNneka
Key Words: classroom environment, formative assessment, formative feedback, higher order, thinking. ... plays in promoting higher order thinking in classrooms, though the majority of the studies in the literature on ..... characteristics; novelty, complexity, and creativity, were identified and measured on a. 7-point scale in a ...
A Seeming Problem for Higher-Order Theories of Consciousness
Mulder, J.M.
Higher-order theories account for intransitive consciousness by using the transitive notion ‘awareness-of.’ I argue that this notion implies a form of ‘seeming’ that the higher-order approach requires, yet cannot account for. I show that, if the relevant kind of seeming is declared to be present in
Characteristic bisimulation for higher-order session processes
Kouzapas, Dimitrios; Pérez, Jorge A.; Yoshida, Nobuko
For higher-order (process) languages, characterising contextual equivalence is a long-standing issue. In the setting of a higher-order ππ -calculus with session types, we develop characteristic bisimilarity, a typed bisimilarity which fully characterises contextual equivalence. To our knowledge,
Higher order comoments of multifactor models and asset allocation
Boudt, K.M.R.; Lu, W.; Peeters, B.
2015-01-01
Accurate estimates of the higher order comoments are needed in asset allocation. We derive explicit formulas for the higher order comoments under the assumption that stock returns are generated by a multifactor model and show that this assumption leads to a substantial reduction in the number of
Higher-order Gaussian kernel in bootstrap boosting algorithm ...
African Journals Online (AJOL)
The bootstrap boosting algorithm is a bias reduction scheme. The adoption of higher-order Gaussian kernel in a bootstrap boosting algorithm in kernel density estimation was investigated. The algorithm used the higher-order. Gaussian kernel instead of the regular fixed kernels. A comparison of the scheme with existing ...
Improved Multilevel Fast Multipole Method for Higher-Order discretizations
DEFF Research Database (Denmark)
Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik
2014-01-01
The Multilevel Fast Multipole Method (MLFMM) allows for a reduced computational complexity when solving electromagnetic scattering problems. Combining this with the reduced number of unknowns provided by Higher-Order discretizations has proven to be a difficult task, with the general conclusion...... being that going above 2nd order is not worthwhile. In this paper, we challenge this conclusion, providing results that demonstrate the potential performance gains with Higher-Order MLFMM and showing some modifications to the traditional MLFMM that can benefit both Higher-Order and standard...
Higher order factors of personality: do they exist?
Ashton, Michael C; Lee, Kibeom; Goldberg, Lewis R; de Vries, Reinout E
2009-05-01
Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher order factors of personality. The authors show that correlations between measures of broad personality factors do not necessarily imply the existence of higher order factors and might instead be due to variables that represent same-signed blends of orthogonal factors. Therefore, the hypotheses of higher order factors and blended variables can only be tested with data on lower level personality variables that define the personality factors. The authors compared the higher order factor model and the blended variable model in three participant samples using the Big Five Aspect Scales, and found better fit for the latter model. In other analyses using the HEXACO Personality Inventory, they identified mutually uncorrelated markers of six personality factors. The authors conclude that correlations between personality factor scales can be explained without postulating any higher order dimensions of personality.
Higher-order momentum distributions and locally affine LDDMM registration
DEFF Research Database (Denmark)
Sommer, Stefan Horst; Nielsen, Mads; Darkner, Sune
2013-01-01
higher-order momentum distributions in the large deformation diffeomorphic metric mapping (LDDMM) registration framework. While the zeroth-order moments previously used in LDDMM only describe local displacement, the first-order momenta that are proposed here represent a basis that allows local...
Higher-order Kerr effect and harmonic cascading in gases
Bache, Morten; Eilenberger, Falk; Minardi, Stefano
2012-01-01
The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE sat...
Higher Order Fractional Stable Motion: Hyperdiffusion with Heavy Tails
Kawai, Reiichiro
2016-10-01
We introduce the class of higher order fractional stable motions that can exhibit hyperdiffusive spreading with heavy tails. We define the class as a generalization of higher order fractional Brownian motion as well as a generalization of linear fractional stable motions. Higher order fractional stable motions are self-similar with Hurst index larger than one and non-Gaussian stable marginals with infinite variance and have stationary higher order increments. We investigate their sample path properties and asymptotic dependence structure on the basis of codifference. In particular, by incrementing or decrementing sample paths once under suitable conditions, the diffusion rate can be accelerated or decelerated by one order. With a view towards simulation study, we provide a ready-for-use sample path simulation recipe at discrete times along with error analysis. The proposed simulation scheme requires only elementary numerical operations and is robust to high frequency sampling, irregular spacing and super-sampling.
On higher order geometric and renormalization group flows
Prabhu, Kartik; Das, Sanjit; Kar, Sayan
2011-10-01
Renormalization group (RG) flows of the bosonic nonlinear σ-model are governed, perturbatively, at different orders of α', by perturbatively evaluated β-functions. In regions where {α'}/{Rc2}≪1 ( {1}/{Rc2} represents the curvature scale), the flow equations at various orders in α' can be thought of as approximating the full, non-perturbative RG flow. On the other hand, taking a different viewpoint, we may consider the above-mentioned RG flow equations as viable geometric flows in their own right, without any reference to the RG aspect. Looked at as purely geometric flows where higher order terms appear, we no longer have the perturbative restrictions (small curvatures). In this paper, we perform our analysis from both these perspectives using specific target manifolds such as S2, H2, unwarped S2×H2 and simple warped products. We analyse and solve the higher order RG flow equations within the appropriate perturbative domains and find the corrections arising due to the inclusion of higher order terms. Such corrections, within the perturbative regime, are shown to be small and they provide an estimate of the error that arises when higher orders are ignored. We also investigate higher order geometric flows on the same manifolds and figure out generic features of geometric evolution, the appearance of singularities and solitons. The aim, in this context, is to demonstrate the role of higher order terms in modifying the flow. One interesting aspect of our analysis is that, separable solutions of the higher order flow equations for simple warped spacetimes (of the kind used in bulk-brane models with a single extra dimension), correspond to constant curvature anti de Sitter (AdS) spacetimes, modulo an overall flow parameter dependent scale factor. The functional form of this scale factor (that we obtain) changes on the inclusion of successive higher order terms in the flow.
Modeling Human Behaviour with Higher Order Logic: Insider Threats
DEFF Research Database (Denmark)
Boender, Jaap; Ivanova, Marieta Georgieva; Kammuller, Florian
2014-01-01
to and implemented in Higher Order Logic. We validate this working hypothesis by revisiting Weber’s understanding explanation. We focus on constructive realism in the context of logical explanation. We review Higher Order Logic (HOL) as a foundation for computer science and summarize its use of theories relating...... it to the sociological process of logical explanation. As a case study on modeling human behaviour, we present the modeling and analysis of insider threats as a Higher Order Logic theory in Isabelle/HOL. We show how each of the three step process of sociological explanation can be seen in our modeling of insider’s state...
Higher order nonlinear degenerate elliptic problems with weak monotonicity
Directory of Open Access Journals (Sweden)
Youssef Akdim
2006-09-01
Full Text Available We prove the existence of solutions for nonlinear degenerate elliptic boundary-value problems of higher order. Solutions are obtained using pseudo-monotonicity theory in a suitable weighted Sobolev space.
Higher order microfibre modes for dielectric particle trapping and propulsion
Maimaiti, Aili; Sergides, Marios; Gusachenko, Ivan; Chormaic, Síle Nic
2014-01-01
Optical manipulation in the vicinity of optical micro- and nanofibres has shown potential across several fields in recent years, including microparticle control, and cold atom probing and trapping. To date, most work has focussed on propagation of the fundamental mode through the fibre. However, along the maximum mode intensity axis, higher order modes have a longer evanescent field extension and larger field amplitude at the fibre waist compared to the fundamental mode, opening up new possibilities for optical manipulation and particle trapping. In this work, we demonstrate a microfibre/optical tweezers compact system for trapping and propelling dielectric particles based on the excitation of the first group of higher order modes at the fibre waist. Single polystyrene particles were trapped and propelled in the evanescent fields of higher order and fundamental modes near the surface of microfibres. Speed enhancement of particle propulsion was observed for the higher order modes compared to the fundamental mo...
Generating superpositions of higher order bessel beams [Conference paper
CSIR Research Space (South Africa)
Vasilyeu, R
2009-10-01
Full Text Available An experimental setup to generate a superposition of higher-order Bessel beams by means of a spatial light modulator and ring aperture is presented. The experimentally produced fields are in good agreement with those calculated theoretically....
Unambiguous formalism for higher order Lagrangian field theories
Energy Technology Data Exchange (ETDEWEB)
Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn [Instituto de Ciencias Matematicas, CSIC-UAM-UC3M-UCM, Serrano 123, 28006 Madrid (Spain); Vankerschaver, Joris [Control and Dynamical Systems, California Institute of Technology, CA (United States)], E-mail: cedricmc@imaff.cfmac.csic.es, E-mail: mdeleon@imaff.cfmac.csic.es, E-mail: d.martin@imaff.cfmac.csic.es, E-mail: jv@caltech.edu
2009-11-27
The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.
Predictors of third and Higher order births in India
Payal Singh; Akash Mishra; OP Mishra
2015-01-01
Background: Total fertility rate (TFR) reflecting population growth is closely related to higher order parity progression. Many Indian states reached replacement level of TFR, but still states constituting nearly 40% population are with TFR ≥ 3. The predictors are the desire of son’s, poor contraceptives practices, younger age at marriage, child loss and shorter birth spacing. Objective: This analysis assessed the degree of relation of 3rd and higher order parity progression with the above me...
All-fiber Raman Probe using Higher Order Modes
DEFF Research Database (Denmark)
Larsen, Stine Højer Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten
2013-01-01
We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes.......We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes....
Higher order aberrations of the eye: Part one
Directory of Open Access Journals (Sweden)
Marsha Oberholzer
2016-03-01
Full Text Available This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer
Linear matrix differential equations of higher-order and applications
Directory of Open Access Journals (Sweden)
Mustapha Rachidi
2008-07-01
Full Text Available In this article, we study linear differential equations of higher-order whose coefficients are square matrices. The combinatorial method for computing the matrix powers and exponential is adopted. New formulas representing auxiliary results are obtained. This allows us to prove properties of a large class of linear matrix differential equations of higher-order, in particular results of Apostol and Kolodner are recovered. Also illustrative examples and applications are presented.
Higher Order Hierarchical Legendre Basis Functions for Electromagnetic Modeling
DEFF Research Database (Denmark)
Jørgensen, Erik; Volakis, John L.; Meincke, Peter
2004-01-01
This paper presents a new hierarchical basis of arbitrary order for integral equations solved with the Method of Moments (MoM). The basis is derived from orthogonal Legendre polynomials which are modified to impose continuity of vector quantities between neighboring elements while maintaining most....... In addition, all higher-order terms in the expansion have two vanishing moments.In contrast to existing formulations, these properties allow the use of very high-order basis functions without introducing ill-conditioning of the resulting MoM matrix. Numerical results confirm that the condition number...... of the MoM matrix obtained with this new basis is much lower than existing higher-order interpolatory and hierarchical basis functions. As a consequence of the excellent condition numbers, we demonstrate that even very high-order MoM systems, e.g. 10th order, can be solved efficiently with an iterative...
Meta-Logical Reasoning in Higher-Order Logic
DEFF Research Database (Denmark)
Villadsen, Jørgen; Schlichtkrull, Anders; Hess, Andreas Viktor
The semantics of first-order logic (FOL) can be described in the meta-language of higher-order logic (HOL). Using HOL one can prove key properties of FOL such as soundness and completeness. Furthermore, one can prove sentences in FOL valid using the formalized FOL semantics. To aid...
Higher-Order Integral Equation Methods in Computational Electromagnetics
DEFF Research Database (Denmark)
Jørgensen, Erik; Meincke, Peter
Higher-order integral equation methods have been investigated. The study has focused on improving the accuracy and efficiency of the Method of Moments (MoM) applied to electromagnetic problems. A new set of hierarchical Legendre basis functions of arbitrary order is developed. The new basis...
Eigenvalue Problem of Nonlinear Semipositone Higher Order Fractional Differential Equations
Directory of Open Access Journals (Sweden)
Jing Wu
2012-01-01
Full Text Available We study the eigenvalue interval for the existence of positive solutions to a semipositone higher order fractional differential equation = = where , , , , satisfying , is the standard Riemann-Liouville derivative, , and is allowed to be changing-sign. By using reducing order method, the eigenvalue interval of existence for positive solutions is obtained.
Positive solutions for higher order singular p-Laplacian boundary ...
Indian Academy of Sciences (India)
of positive solutions for sublinear 2m-th order singular p-Laplacian BVPs on closed interval. Keywords. Positive solution; singular BVPs; sufficient and necessary conditions; p-Laplacian equations. 1. Introduction. In this paper, we are concerned with higher order singular p-Laplacian boundary value problems. ⎧. ⎨. ⎩.
Higher-order Kerr effect and harmonic cascading in gases
DEFF Research Database (Denmark)
Bache, Morten; Eilenberger, Falk; Minardi, Stefano
2012-01-01
The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher......-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE saturation intensity, while for longer wavelengths cascading will decrease the HOKE saturation intensity....
Higher-order Kerr effect and harmonic cascading in gases.
Bache, Morten; Eilenberger, Falk; Minardi, Stefano
2012-11-15
The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE saturation intensity, while for longer wavelengths cascading will decrease the HOKE saturation intensity.
The Cauchy problem for higher order abstract differential equations
Xiao, Ti-Jun
1998-01-01
This monograph is the first systematic exposition of the theory of the Cauchy problem for higher order abstract linear differential equations, which covers all the main aspects of the developed theory. The main results are complete with detailed proofs and established recently, containing the corresponding theorems for first and incomplete second order cases and therefore for operator semigroups and cosine functions. They will find applications in many fields. The special power of treating the higher order problems directly is demonstrated, as well as that of the vector-valued Laplace transforms in dealing with operator differential equations and operator families. The reader is expected to have a knowledge of complex and functional analysis.
Multilevel Fast Multipole Method for Higher Order Discretizations
DEFF Research Database (Denmark)
Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik
2014-01-01
The multi-level fast multipole method (MLFMM) for a higher order (HO) discretization is demonstrated on high-frequency (HF) problems, illustrating for the first time how an efficient MLFMM for HO can be achieved even for very large groups. Applying several novel ideas, beneficial to both lower...... order and higher order discretizations, results from a low-memory, high-speed MLFMM implementation of a HO hierarchical discretization are shown. These results challenge the general view that the benefits of HO and HF-MLFMM cannot be combined....
Practical Programming with Higher-Order Encodings and Dependent Types
DEFF Research Database (Denmark)
Poswolsky, Adam; Schürmann, Carsten
2008-01-01
, tedious, and error-prone. In this paper, we describe the underlying calculus of Delphin. Delphin is a fully implemented functional-programming language supporting reasoning over higher-order encodings and dependent types, while maintaining the benefits of HOAS. More specifically, just as representations......Higher-order abstract syntax (HOAS) refers to the technique of representing variables of an object-language using variables of a meta-language. The standard first-order alternatives force the programmer to deal with superficial concerns such as substitutions, whose implementation is often routine...
Tensor Spectral Clustering for Partitioning Higher-order Network Structures.
Benson, Austin R; Gleich, David F; Leskovec, Jure
2015-01-01
Spectral graph theory-based methods represent an important class of tools for studying the structure of networks. Spectral methods are based on a first-order Markov chain derived from a random walk on the graph and thus they cannot take advantage of important higher-order network substructures such as triangles, cycles, and feed-forward loops. Here we propose a Tensor Spectral Clustering (TSC) algorithm that allows for modeling higher-order network structures in a graph partitioning framework. Our TSC algorithm allows the user to specify which higher-order network structures (cycles, feed-forward loops, etc.) should be preserved by the network clustering. Higher-order network structures of interest are represented using a tensor, which we then partition by developing a multilinear spectral method. Our framework can be applied to discovering layered flows in networks as well as graph anomaly detection, which we illustrate on synthetic networks. In directed networks, a higher-order structure of particular interest is the directed 3-cycle, which captures feedback loops in networks. We demonstrate that our TSC algorithm produces large partitions that cut fewer directed 3-cycles than standard spectral clustering algorithms.
Binocular visual performance and summation after correcting higher order aberrations.
Sabesan, Ramkumar; Zheleznyak, Len; Yoon, Geunyoung
2012-12-01
Although the ocular higher order aberrations degrade the retinal image substantially, most studies have investigated their effect on vision only under monocular conditions. Here, we have investigated the impact of binocular higher order aberration correction on visual performance and binocular summation by constructing a binocular adaptive optics (AO) vision simulator. Binocular monochromatic aberration correction using AO improved visual acuity and contrast sensitivity significantly. The improvement however, differed from that achieved under monocular viewing. At high spatial frequency (24 c/deg), the monocular benefit in contrast sensitivity was significantly larger than the benefit achieved binocularly. In addition, binocular summation for higher spatial frequencies was the largest in the presence of subject's native higher order aberrations and was reduced when these aberrations were corrected. This study thus demonstrates the vast potential of binocular AO vision testing in understanding the impact of ocular optics on habitual binocular vision.
Li, C.; Liu, K.-Y.; Li, F.
2007-05-01
Design and performance of a coplanar waveguide (CPW) bandpass filter (BPF) using composite right/left-handed (CRLH) zeroth-order resonators have been studied. The unit cell of the CRLH CPW consists of a series interdigital capacitor and two shunt stub inductors embedded between two sections of CPWs. The Bloch analysis is applied based on the S parameters to derive the characteristics of the eigen modes (Bloch modes), from which the right/left-handed frequency band and the zeroth-order resonant frequency are clearly determined. Then, the susceptance slope parameter of the resonator is extracted and the admittance (J-) inverters are introduced to synthesize a capacitively coupled CPW BPF. The measured performance agrees with the simulated one. They show that the size of the filter is greatly reduced (more than 60%) when compared to a conventional structure.
Higher order theories and their relationship with noncommutativity
Energy Technology Data Exchange (ETDEWEB)
Sánchez-Santos, Oscar, E-mail: oscarsanbuzz@yahoo.com.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, C.P. 09340, México D.F., México (Mexico); Vergara, José David, E-mail: vergara@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, C.P. 04510, México D.F., México (Mexico)
2014-06-13
We present a relationship between noncommutativity and higher order time derivative theories using a perturbation method. We make a generalization of the Chern–Simons quantum mechanics for higher order time derivatives. This model presents noncommutativity in a natural way when we project to low-energy physical states without the necessity of taking the strong field limit. We quantize the theory using a Bopp's shift of the noncommutative variables and we obtain a spectrum without negative energies, under the perturbation limits. In addition, we extent the model to high order time derivatives and noncommutativity with variable dependent parameter. - Highlights: • We show a relationship between high order derivative theories and noncommutativity. • The noncommutativity appears when we project to low-energy physical states. • We extend the model to high order time derivatives. • We include cases with variable dependent noncommutative parameter.
Almeida, Gustavo F. B.; Almeida, Juliana M. P.; Martins, Renato J.; De Boni, Leonardo; Arnold, Craig B.; Mendonca, Cleber R.
2018-01-01
The development of advanced photonics devices requires materials with large optical nonlinearities, fast response times and high optical transparency, while at the same time allowing for the micro/nano-processing needed for integrated photonics. In this context, glasses have been receiving considerable attention given their relevant optical properties which can be specifically tailored by compositional control. Corning Gorilla® Glass (strengthened alkali aluminosilicate glass) is well-known for its use as a protective screen in mobile devices, and has attracted interest as a potential candidate for optical devices. Therefore, it is crucial not only to expand the knowledge on the fabrication of waveguides in Gorilla Glass under different regimes, but also to determine its nonlinear optical response, both using fs-laser pulses. Thus, this paper reports, for the first time, characterization of the third-order optical nonlinearities of Gorilla Glass, as well as linear and nonlinear characterization of waveguide written with femtosecond pulses under the low repetition rate regime (1 kHz).
A simple higher-order theory for laminated composite plates
Reddy, J. N.
1984-01-01
A higher-order shear deformation theory of laminated composite plates is developed. The theory contains the same dependent unknowns as in the first-order shear deformation theory of Whitney and Pagano (1970), but accounts for parabolic distribution of the transverse shear strains through the thickness of the plate. Exact closed-form solutions of symmetric cross-ply laminates are obtained and the results are compared with three-dimensional elasticity solutions and first-order shear deformation theory solutions. The present theory predicts the deflections and stresses more accurately when compared to the first-order theory.
Higher-Order Factors of Personality: Do They Exist?
Ashton, Michael C.; Lee, Kibeom; Goldberg, Lewis R.; de Vries, Reinout E.
2010-01-01
Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher-order factors of personality. We show that correlations between measures of broad personality factors do not necessarily imply the existence of higher-order factors, and might instead be due to variables that represent same-signed blends of orthogonal factors. Therefore, the hypotheses of higher-order factors and blended variables can only be tested with data on lower-level personality variables that define the personality factors. We compared the higher-order factor model and the blended variable model in three participant samples using the Big Five Aspect Scales, and found better fit for the latter model. In other analyses using the HEXACO Personality Inventory, we identified mutually uncorrelated markers of six personality factors. We conclude that correlations between personality factor scales can be explained without postulating any higher-order dimensions of personality. PMID:19458345
Dynamics and control of higher-order nonholonomic systems
Rubio Hervas, Jaime
A theoretical framework is established for the control of higher-order nonholonomic systems, defined as systems that satisfy higher-order nonintegrable constraints. A model for such systems is developed in terms of differential-algebraic equations defined on a higher-order tangent bundle. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are presented. Higher-order nonholonomic systems are shown to be strongly accessible and, under certain conditions, small time locally controllable at any equilibrium. There are important examples of higher-order nonholonomic systems that are asymptotically stabilizable via smooth feedback, including space vehicles with multiple slosh modes and Prismatic-Prismatic-Revolute (PPR) robots moving open liquid containers, as well as an interesting class of systems that do not admit asymptotically stabilizing continuous static or dynamic state feedback. Specific assumptions are introduced to define this class, which includes important examples of robotic systems. A discontinuous nonlinear feedback control algorithm is developed to steer any initial state to the equilibrium at the origin. The applicability of the theoretical development is illustrated through two examples: control of a planar PPR robot manipulator subject to a jerk constraint and control of a point mass moving on a constant torsion curve in a three dimensional space.
Higher order QCD corrections in small x physics
Energy Technology Data Exchange (ETDEWEB)
Chachamis, G.
2006-11-15
We study higher order QCD corrections in small x Physics. The numerical implementation of the full NLO photon impact factor is the remaining necessary piece for the testing of the NLO BFKL resummation against data from physical processes, such as {gamma}{sup *}{gamma}{sup *} collisions. We perform the numerical integration over phase space for the virtual corrections to the NLO photon impact factor. This, along with the previously calculated real corrections, makes feasible in the near future first estimates for the {gamma}*{gamma}* total cross section, since the convolution of the full impact factor with the NLO BFKL gluon Green's function is now straightforward. The NLO corrections for the photon impact factor are sizeable and negative. In the second part of this thesis, we estimate higher order correction to the BK equation. We are mainly interested in whether partonic saturation delays or not in rapidity when going beyond the leading order. In our investigation, we use the so called 'rapidity veto' which forbid two emissions to be very close in rapidity, to 'switch on' higher order corrections to the BK equation. From analytic and numerical analysis, we conclude that indeed saturation does delay in rapidity when higher order corrections are taken into account. In the last part, we investigate higher order QCD corrections as additional corrections to the Electroweak (EW) sector. The question of whether BFKL corrections are of any importance in the Regge limit for the EW sector seems natural; although they arise in higher loop level, the accumulation of logarithms in energy s at high energies, cannot be dismissed without an investigation. We focus on the process {gamma}{gamma}{yields}ZZ. We calculate the pQCD corrections in the forward region at leading logarithmic (LL) BFKL accuracy, which are of the order of few percent at the TeV energy scale. (orig.)
Filtering of higher-order laser modes using plasma structures
Djordjevic, Blagoje; Benedetti, Carlo; Schroeder, Carl; Esarey, Eric; Leemans, Wim
2017-10-01
Plasma structures based on leaky channels are proposed to filter higher-order laser mode content. The evolution and propagation of non-Gaussian laser pulses in leaky channels is studied, and it is shown that, for appropriate laser-plasma parameters, the higher-order laser mode content may be removed while the fundamental mode remains well-guided. The behavior of the multi-mode laser pulse is described analytically, including the derivation of the leakage coefficients, and compared to numerical calculations. Gaussian laser pulse propagation, without higher-order mode content, improves guiding in parabolic plasma channels, enabling extended interaction lengths for laser-plasma accelerator applications. This work was supported by the Director, Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Higher-order modulation instability in nonlinear fiber optics.
Erkintalo, Miro; Hammani, Kamal; Kibler, Bertrand; Finot, Christophe; Akhmediev, Nail; Dudley, John M; Genty, Goëry
2011-12-16
We report theoretical, numerical, and experimental studies of higher-order modulation instability in the focusing nonlinear Schrödinger equation. This higher-order instability arises from the nonlinear superposition of elementary instabilities, associated with initial single breather evolution followed by a regime of complex, yet deterministic, pulse splitting. We analytically describe the process using the Darboux transformation and compare with experiments in optical fiber. We show how a suitably low frequency modulation on a continuous wave field induces higher-order modulation instability splitting with the pulse characteristics at different phases of evolution related by a simple scaling relationship. We anticipate that similar processes are likely to be observed in many other systems including plasmas, Bose-Einstein condensates, and deep water waves. © 2011 American Physical Society
Block variable order step size method for solving higher order orbital problems
Rasedee, Ahmad Fadly Nurullah; Ijam, Hazizah Mohd; Sathar, Mohammad Hasan Abdul; Ishak, Norizarina; Nazri, Muhamad Azrin; Kamarudin, Nur Shuhada; Ramli, Nur Ainna
2017-11-01
Previous numerical methods for solving systems of higher order ordinary differential equations (ODEs) directly require calculating the integration coefficients at every step. This research provides a block multi step method for solving orbital problems with periodic solutions in the form of higher order ODEs directly. The advantage of the proposed method is, it requires calculating the integration coefficients only once at the beginning of the integration is presented. The derived formulae is then validated by running simulations with known higher order orbital equations. To provide further efficiency, a relationship between integration coefficients of various order is obtained.
Numerical evidence for higher order Stark-type conjectures
McGown, Kevin,; Sands, Jonathan; Vallières, Daniel
2017-01-01
We give a systematic method of providing numerical evidence for higher order Stark-type conjectures such as (in chronological order) Stark's conjecture over $\\mathbb{Q}$, Rubin's conjecture, Popescu's conjecture, and a conjecture due to Burns that constitutes a generalization of Brumer's classical conjecture on annihilation of class groups. Our approach is general and could be used for any abelian extension of number fields, independent of the signature and type of places (finite or infinite)...
Oscillation of solutions of some higher order linear differential equations
Directory of Open Access Journals (Sweden)
Hong-Yan Xu
2009-11-01
Full Text Available In this paper, we deal with the order of growth and the hyper order of solutions of higher order linear differential equations $$f^{(k}+B_{k-1}f^{(k-1}+\\cdots+B_1f'+B_0f=F$$ where $B_j(z (j=0,1,\\ldots,k-1$ and $F$ are entire functions or polynomials. Some results are obtained which improve and extend previous results given by Z.-X. Chen, J. Wang, T.-B. Cao and C.-H. Li.
Thermodynamics of higher dimensional black holes with higher order thermal fluctuations
Pourhassan, B.; Kokabi, K.; Rangyan, S.
2017-12-01
In this paper, we consider higher order corrections of the entropy, which coming from thermal fluctuations, and find their effect on the thermodynamics of higher dimensional charged black holes. Leading order thermal fluctuation is logarithmic term in the entropy while higher order correction is proportional to the inverse of original entropy. We calculate some thermodynamics quantities and obtain the effect of logarithmic and higher order corrections of entropy on them. Validity of the first law of thermodynamics investigated and Van der Waals equation of state of dual picture studied. We find that five-dimensional black hole behaves as Van der Waals, but higher dimensional case have not such behavior. We find that thermal fluctuations are important in stability of black hole hence affect unstable/stable black hole phase transition.
Enhancing Higher Order Thinking Skills through Clinical Simulation
Varutharaju, Elengovan; Ratnavadivel, Nagendralingan
2014-01-01
Purpose: The study aimed to explore, describe and analyse the design and implementation of clinical simulation as a pedagogical tool in bridging the deficiency of higher order thinking skills among para-medical students, and to make recommendations on incorporating clinical simulation as a pedagogical tool to enhance thinking skills and align the…
On the Constitution and Configuration of Higher-order Compounds
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. On the Constitution and Configuration of Higher-order Compounds. Alfred Werner. Reflections Volume 4 Issue 9 September 1999 pp 90-94. Fulltext. Click here to view fulltext PDF. Permanent link:
Numerical methods of higher order of accuracy for incompressible flows
Czech Academy of Sciences Publication Activity Database
Kozel, K.; Louda, Petr; Příhoda, Jaromír
2010-01-01
Roč. 80, č. 8 (2010), s. 1734-1745 ISSN 0378-4754 Institutional research plan: CEZ:AV0Z20760514 Keywords : higher order methods * upwind methods * backward-facing step Subject RIV: BK - Fluid Dynamics Impact factor: 0.812, year: 2010
Higher-Order Hierarchical Legendre Basis Functions in Applications
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2007-01-01
degree of orthogonality. The basis functions are well-suited for solution of complex electromagnetic problems involving multiple homogeneous or inhomogeneous dielectric regions, metallic surfaces, layered media, etc. This paper presents real-life complex antenna radiation problems modeled...... with electromagnetic simulation tools based on the higher-order hierarchical Legendre basis functions....
Stochastic and Higher-Order Effects on Exploding Pulses
Directory of Open Access Journals (Sweden)
Orazio Descalzi
2017-08-01
Full Text Available The influence of additive noise, multiplicative noise, and higher-order effects on exploding solitons in the framework of the prototype complex cubic-quintic Ginzburg-Landau equation is studied. Transitions from explosions to filling-in to the noisy spatially homogeneous finite amplitude solution, collapse (zero solution, and periodic exploding dissipative solitons are reported.
Recent Advances in Higher-Order, Multimodal, Biomedical Imaging Agents.
Rieffel, James; Chitgupi, Upendra; Lovell, Jonathan F
2015-09-16
Advances in biomedical imaging have spurred the development of integrated multimodal scanners, usually capable of two simultaneous imaging modes. The long-term vision of higher-order multimodality is to improve diagnostics or guidance through the analysis of complementary, data-rich, co-registered images. Synergies achieved through combined modalities could enable researchers to better track diverse physiological and structural events, analyze biodistribution and treatment efficacy, and compare established and emerging modalities. Higher-order multimodal approaches stand to benefit from molecular imaging probes and, in recent years, contrast agents that have hypermodal characteristics have increasingly been reported in preclinical studies. Given the chemical requirements for contrast agents representing various modalities to be integrated into a single entity, the higher-order multimodal agents reported so far tend to be of nanoparticulate form. To date, the majority of reported nanoparticles have included components that are active for magnetic resonance. Herein, recent progress in higher-order multimodal imaging agents is reviewed, spanning a range of material and structural classes, and demonstrating utility in three (or more) imaging modalities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Impact of higher-order dispersion in the modulational instability ...
Indian Academy of Sciences (India)
2014-02-08
Feb 8, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 2. Impact of higher-order dispersion in the modulational instability spectrum of a relaxing coupled saturable media. K Nithyanandan R Vasantha Jayakantha Raja T Uthayakumar K Porsezian. Contributed Papers Volume 82 Issue 2 February ...
Higher-Order Item Response Models for Hierarchical Latent Traits
Huang, Hung-Yu; Wang, Wen-Chung; Chen, Po-Hsi; Su, Chi-Ming
2013-01-01
Many latent traits in the human sciences have a hierarchical structure. This study aimed to develop a new class of higher order item response theory models for hierarchical latent traits that are flexible in accommodating both dichotomous and polytomous items, to estimate both item and person parameters jointly, to allow users to specify…
New higher-order transition in causal dynamical triangulations
Ambjorn, J.; Coumbe, D.; Gizbert-Studnicki, J.; Gorlich, A.; Jurkiewicz, J.
2017-01-01
We reinvestigate the recently discovered bifurcation phase transition in causal dynamical triangulations and provide further evidence that it is a higher-order transition. We also investigate the impact of introducing matter in the form of massless scalar fields to causal dynamical triangulations.
Squeezing of higher order Hermite-Gauss modes
DEFF Research Database (Denmark)
Lassen, Mikael Østergaard
2008-01-01
The present paper gives an overview of the experimental generation of squeezing in higher order Hermite-Gaussian modes with an optical parametric ampli¯er (OPA). This work was awarded with The European Optical Society (EOS) price 2007. The purpose of the prize is to encourage a European dimension...
Decidable Fragments of a Higher Order Calculus with Locations
DEFF Research Database (Denmark)
Hüttel, Hans; Godskesen, Jens Christian; Haagensen, Bjørn
2009-01-01
Homer is a higher order process calculus with locations. In this paper we study Homer in the setting of the semantic finite control property, which is a finite reachability criterion that implies decidability of barbed bisimilarity. We show that strong and weak barbed bisimilarity are undecidable...... control π-calculus in Homer....
Building Higher-Order Markov Chain Models with EXCEL
Ching, Wai-Ki; Fung, Eric S.; Ng, Michael K.
2004-01-01
Categorical data sequences occur in many applications such as forecasting, data mining and bioinformatics. In this note, we present higher-order Markov chain models for modelling categorical data sequences with an efficient algorithm for solving the model parameters. The algorithm can be implemented easily in a Microsoft EXCEL worksheet. We give a…
Constrained variational calculus for higher order classical field theories
Energy Technology Data Exchange (ETDEWEB)
Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn, E-mail: cedricmc@icmat.e, E-mail: mdeleon@icmat.e, E-mail: david.martin@icmat.e [Instituto de Ciencias Matematicas, CSIC-UAM-UC3M-UCM, Serrano 123, 28006 Madrid (Spain)
2010-11-12
We develop an intrinsic geometrical setting for higher order constrained field theories. As a main tool we use an appropriate generalization of the classical Skinner-Rusk formalism. Some examples of applications are studied, in particular to the geometrical description of optimal control theory for partial differential equations.
Higher-order factors of personality: Do they exist?
Ashton, M.C.; Lee, K.; Goldberg, L.R.; de Vries, R.E.
2009-01-01
Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher order factors of personality. The authors show that correlations between measures of broad personality factors do not
Higher Order Language Competence and Adolescent Mental Health
Cohen, Nancy J.; Farnia, Fataneh; Im-Bolter, Nancie
2013-01-01
Background: Clinic and community-based epidemiological studies have shown an association between child psychopathology and language impairment. The demands on language for social and academic adjustment shift dramatically during adolescence and the ability to understand the nonliteral meaning in language represented by higher order language…
First Measurements of Higher Order Optics Parameters in the LHC
Vanbavinckhove, G; Bartolini, R; Calaga, R; Giovannozzi, M; Maclean, E H; Miyamoto, R; Schmidt, F; Tomas, R
2011-01-01
Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these pa- rameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed sim- ulations are compared to the measurements together with discussions on the measurement limitations.
Higher order risk attitudes, demographics, and financial decisions
Noussair, C.N.; Trautmann, S.T.; van de Kuilen, G.
We study the prevalence of the higher order risk attitudes of prudence and temperance in an experiment with a large demographically representative sample of participants. Under expected utility, prudence and temperance are defined by a convex first, and concave second, derivative of the utility
Higher-order structure and epidemic dynamics in clustered networks.
Ritchie, Martin; Berthouze, Luc; House, Thomas; Kiss, Istvan Z
2014-05-07
Clustering is typically measured by the ratio of triangles to all triples regardless of whether open or closed. Generating clustered networks, and how clustering affects dynamics on networks, is reasonably well understood for certain classes of networks (Volz et al., 2011; Karrer and Newman, 2010), e.g. networks composed of lines and non-overlapping triangles. In this paper we show that it is possible to generate networks which, despite having the same degree distribution and equal clustering, exhibit different higher-order structure, specifically, overlapping triangles and other order-four (a closed network motif composed of four nodes) structures. To distinguish and quantify these additional structural features, we develop a new network metric capable of measuring order-four structure which, when used alongside traditional network metrics, allows us to more accurately describe a network׳s topology. Three network generation algorithms are considered: a modified configuration model and two rewiring algorithms. By generating homogeneous networks with equal clustering we study and quantify their structural differences, and using SIS (Susceptible-Infected-Susceptible) and SIR (Susceptible-Infected-Recovered) dynamics we investigate computationally how differences in higher-order structure impact on epidemic threshold, final epidemic or prevalence levels and time evolution of epidemics. Our results suggest that characterising and measuring higher-order network structure is needed to advance our understanding of the impact of network topology on dynamics unfolding on the networks. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Higher-Order Separation Logic in Isabelle/HOLCF
DEFF Research Database (Denmark)
Varming, Carsten; Birkedal, Lars
2008-01-01
or greatest fixed points etc. The higher-order logic ensures that we can show non-trivial algorithms correct without having to extend the semantics of the language as was done previously in verifications based on first-order separation logic [2,20]. We provide non-trivial examples to support this claim...... language. This follows the definitional approach common in HOL theorem provers, i.e., the soundness of our model only relies on the soundness of Isabelle/HOL [6]. We use our formalization to give a formally verified proof of Cheney's copying garbage collector [4] using a tagged representation of objects....... The proof generalizes the results in [2]. The proof uses an encoding of the separation logic formula this(h) to capture the heap from before the garbage collection and thus shows another novel use of higher-order separation logic....
Speckle reduction via higher order total variation approach.
Wensen Feng; Hong Lei; Yang Gao
2014-04-01
Multiplicative noise (also known as speckle) reduction is a prerequisite for many image-processing tasks in coherent imaging systems, such as the synthetic aperture radar. One approach extensively used in this area is based on total variation (TV) regularization, which can recover significantly sharp edges of an image, but suffers from the staircase-like artifacts. In order to overcome the undesirable deficiency, we propose two novel models for removing multiplicative noise based on total generalized variation (TGV) penalty. The TGV regularization has been mathematically proven to be able to eliminate the staircasing artifacts by being aware of higher order smoothness. Furthermore, an efficient algorithm is developed for solving the TGV-based optimization problems. Numerical experiments demonstrate that our proposed methods achieve state-of-the-art results, both visually and quantitatively. In particular, when the image has some higher order smoothness, our methods outperform the TV-based algorithms.
Higher-Order Cyclostationarity Detection for Spectrum Sensing
Directory of Open Access Journals (Sweden)
Julien Renard
2010-01-01
Full Text Available Recent years have shown a growing interest in the concept of Cognitive Radios (CRs, able to access portions of the electromagnetic spectrum in an opportunistic operating way. Such systems require efficient detectors able to work in low Signal-to-Noise Ratio (SNR environments, with little or no information about the signals they are trying to detect. Energy detectors are widely used to perform such blind detection tasks, but quickly reach the so-called SNR wall below which detection becomes impossible Tandra (2005. Cyclostationarity detectors are an interesting alternative to energy detectors, as they exploit hidden periodicities present in man-made signals, but absent in noise. Such detectors use quadratic transformations of the signals to extract the hidden sine-waves. While most of the literature focuses on the second-order transformations of the signals, we investigate the potential of higher-order transformations of the signals. Using the theory of Higher-Order Cyclostationarity (HOCS, we derive a fourth-order detector that performs similarly to the second-order ones to detect linearly modulated signals, at SNR around 0 dB, which may be used if the signals of interest do not exhibit second-order cyclostationarity. More generally this paper reviews the relevant aspects of the cyclostationary and HOCS theory, and shows their potential for spectrum sensing.
Gibson, Emily Abbott
comparable efficiency to emission from neutral atoms thereby showing that high harmonic emission is not limited by the saturation intensity, or the intensity at which the medium is fully ionized, but can extend to much higher photon energies.[30] Both results were obtained by using a waveguide geometry for HHG, allowing manipulation of the phase matching conditions and reducing the detrimental effects of ionization. The ideas from this work are expected to increase the number of applications of high harmonic generation as a light source by increasing the efficiency of the process and opening up the possibility of generating multi-keV photon energies.
Higher order correlation beams in atmosphere under strong turbulence conditions.
Avetisyan, H; Monken, C H
2016-02-08
Higher order correlation beams, that is, two-photon beams obtained from the process of spontaneous parametric down-conversion pumped by Hermite-Gauss or Laguerre-Gauss beams of any order, can be used to encode information in many modes, opening the possibility of quantum communication with large alphabets. In this paper we calculate, analytically, the fourth-order correlation function for the Hermite-Gauss and Laguerre-Gauss coherent and partially coherent correlation beams propagating through a strong turbulent medium. We show that fourth-order correlation functions for correlation beams have, under certain conditions, expressions similar to those of intensities of classical beams and are degraded by turbulence in a similar way as the classical beams. Our results can be useful in establishing limits for the use of two-photon beams in quantum communications with larger alphabets under atmospheric turbulence.
Higher-order techniques for some problems of nonlinear control
Directory of Open Access Journals (Sweden)
Sarychev Andrey V.
2002-01-01
Full Text Available A natural first step when dealing with a nonlinear problem is an application of some version of linearization principle. This includes the well known linearization principles for controllability, observability and stability and also first-order optimality conditions such as Lagrange multipliers rule or Pontryagin's maximum principle. In many interesting and important problems of nonlinear control the linearization principle fails to provide a solution. In the present paper we provide some examples of how higher-order methods of differential geometric control theory can be used for the study nonlinear control systems in such cases. The presentation includes: nonlinear systems with impulsive and distribution-like inputs; second-order optimality conditions for bang–bang extremals of optimal control problems; methods of high-order averaging for studying stability and stabilization of time-variant control systems.
Transversely isotropic higher-order averaged structure tensors
Hashlamoun, Kotaybah; Federico, Salvatore
2017-08-01
For composites or biological tissues reinforced by statistically oriented fibres, a probability distribution function is often used to describe the orientation of the fibres. The overall effect of the fibres on the material response is accounted for by evaluating averaging integrals over all possible directions in space. The directional average of the structure tensor (tensor product of the unit vector describing the fibre direction by itself) is of high significance. Higher-order averaged structure tensors feature in several models and carry similarly important information. However, their evaluation has a quite high computational cost. This work proposes to introduce mathematical techniques to minimise the computational cost associated with the evaluation of higher-order averaged structure tensors, for the case of a transversely isotropic probability distribution of orientation. A component expression is first introduced, using which a general tensor expression is obtained, in terms of an orthonormal basis in which one of the vectors coincides with the axis of symmetry of transverse isotropy. Then, a higher-order transversely isotropic averaged structure tensor is written in an appropriate basis, constructed starting from the basis of the space of second-order transversely isotropic tensors, which is constituted by the structure tensor and its complement to the identity.
Higher-Order Spectrum in Understanding Nonlinearity in EEG Rhythms
Directory of Open Access Journals (Sweden)
Cauchy Pradhan
2012-01-01
Full Text Available The fundamental nature of the brain's electrical activities recorded as electroencephalogram (EEG remains unknown. Linear stochastic models and spectral estimates are the most common methods for the analysis of EEG because of their robustness, simplicity of interpretation, and apparent association with rhythmic behavioral patterns in nature. In this paper, we extend the use of higher-order spectrum in order to indicate the hidden characteristics of EEG signals that simply do not arise from random processes. The higher-order spectrum is an extension Fourier spectrum that uses higher moments for spectral estimates. This essentially nullifies all Gaussian random effects, therefore, can reveal non-Gaussian and nonlinear characteristics in the complex patterns of EEG time series. The paper demonstrates the distinguishing features of bispectral analysis for chaotic systems, filtered noises, and normal background EEG activity. The bispectrum analysis detects nonlinear interactions; however, it does not quantify the coupling strength. The squared bicoherence in the nonredundant region has been estimated to demonstrate nonlinear coupling. The bicoherence values are minimal for white Gaussian noises (WGNs and filtered noises. Higher bicoherence values in chaotic time series and normal background EEG activities are indicative of nonlinear coupling in these systems. The paper shows utility of bispectral methods as an analytical tool in understanding neural process underlying human EEG patterns.
A linear support higher-order tensor machine for classification.
Hao, Zhifeng; He, Lifang; Chen, Bingqian; Yang, Xiaowei
2013-07-01
There has been growing interest in developing more effective learning machines for tensor classification. At present, most of the existing learning machines, such as support tensor machine (STM), involve nonconvex optimization problems and need to resort to iterative techniques. Obviously, it is very time-consuming and may suffer from local minima. In order to overcome these two shortcomings, in this paper, we present a novel linear support higher-order tensor machine (SHTM) which integrates the merits of linear C-support vector machine (C-SVM) and tensor rank-one decomposition. Theoretically, SHTM is an extension of the linear C-SVM to tensor patterns. When the input patterns are vectors, SHTM degenerates into the standard C-SVM. A set of experiments is conducted on nine second-order face recognition datasets and three third-order gait recognition datasets to illustrate the performance of the proposed SHTM. The statistic test shows that compared with STM and C-SVM with the RBF kernel, SHTM provides significant performance gain in terms of test accuracy and training speed, especially in the case of higher-order tensors.
Uranus, H.P.; Hoekstra, Hugo; van Groesen, Embrecht W.C.
A simple high-order Galerkin finite element scheme is formulated to compute both the guided and leaky modes of anisotropic planar waveguides with a diagonal permitivity tensor. Transparent boundary conditions derived from the Sommerfeld radiation conditions are used to model the fields at the
Promoting higher order thinking skills using inquiry-based learning
Madhuri, G. V.; S. S. N Kantamreddi, V.; Goteti, L. N. S. Prakash
2012-05-01
Active learning pedagogies play an important role in enhancing higher order cognitive skills among the student community. In this work, a laboratory course for first year engineering chemistry is designed and executed using an inquiry-based learning pedagogical approach. The goal of this module is to promote higher order thinking skills in chemistry. Laboratory exercises are designed based on Bloom's taxonomy and a just-in-time facilitation approach is used. A pre-laboratory discussion outlining the theory of the experiment and its relevance is carried out to enable the students to analyse real-life problems. The performance of the students is assessed based on their ability to perform the experiment, design new experiments and correlate practical utility of the course module with real life. The novelty of the present approach lies in the fact that the learning outcomes of the existing experiments are achieved through establishing a relationship with real-world problems.
Comparison Criteria for Nonlinear Functional Dynamic Equations of Higher Order
Directory of Open Access Journals (Sweden)
Taher S. Hassan
2016-01-01
Full Text Available We will consider the higher order functional dynamic equations with mixed nonlinearities of the form xnt+∑j=0Npjtϕγjxφjt=0, on an above-unbounded time scale T, where n≥2, xi(t≔ri(tϕαixi-1Δ(t, i=1,…,n-1, with x0=x, ϕβ(u≔uβsgnu, and α[i,j]≔αi⋯αj. The function φi:T→T is a rd-continuous function such that limt→∞φi(t=∞ for j=0,1,…,N. The results extend and improve some known results in the literature on higher order nonlinear dynamic equations.
Higher-order geodesic deviations applied to the Kerr metric
Colistete, R J; Kerner, R
2002-01-01
Starting with an exact and simple geodesic, we generate approximate geodesics by summing up higher-order geodesic deviations within a general relativistic setting, without using Newtonian and post-Newtonian approximations. We apply this method to the problem of closed orbital motion of test particles in the Kerr metric spacetime. With a simple circular orbit in the equatorial plane taken as the initial geodesic, we obtain finite eccentricity orbits in the form of Taylor series with the eccentricity playing the role of a small parameter. The explicit expressions of these higher-order geodesic deviations are derived using successive systems of linear equations with constant coefficients, whose solutions are of harmonic oscillator type. This scheme gives best results when applied to orbits with low eccentricities, but with arbitrary possible values of (GM/Rc sup 2).
Higher-order symmetries and conservation laws of multi ...
Indian Academy of Sciences (India)
Equation (1) has been extensively studied in terms of their symmetries and variational properties [1]. In particular, the sine-Gordon equation uXT − sin u = 0 has been shown to have higher-order variational symmetries, X = Q∂u. For example,. X1 = (. uXXX +. 1. 2 u3. X. ) ∂u,. X2 = (. uXXXXX +. 5. 2 u2. X uXXX +. 5. 2. uX u2.
Nonresonance impulsive higher order functional nonconvex-valued differential inclusions
Directory of Open Access Journals (Sweden)
Mouffak Benchohra
2002-01-01
Full Text Available In this paper, the authors investigate the existence of solutions for nonresonance impulsive higher order functional differential inclusions in Banach spaces with nonconvex valued right hand side. They present two results. In the first one, they rely on a fixed point theorem for contraction multivalued maps due to Covitz and Nadler, and for the second one, they use Schaefer's fixed point theorem combined with lower semi-continuous multivalued operators with decomposable values.
Enhanced sensitivity at higher-order exceptional points
Hodaei, Hossein; Hassan, Absar U.; Wittek, Steffen; Garcia-Gracia, Hipolito; El-Ganainy, Ramy; Christodoulides, Demetrios N.; Khajavikhan, Mercedeh
2017-08-01
Non-Hermitian degeneracies, also known as exceptional points, have recently emerged as a new way to engineer the response of open physical systems, that is, those that interact with the environment. They correspond to points in parameter space at which the eigenvalues of the underlying system and the corresponding eigenvectors simultaneously coalesce. In optics, the abrupt nature of the phase transitions that are encountered around exceptional points has been shown to lead to many intriguing phenomena, such as loss-induced transparency, unidirectional invisibility, band merging, topological chirality and laser mode selectivity. Recently, it has been shown that the bifurcation properties of second-order non-Hermitian degeneracies can provide a means of enhancing the sensitivity (frequency shifts) of resonant optical structures to external perturbations. Of particular interest is the use of even higher-order exceptional points (greater than second order), which in principle could further amplify the effect of perturbations, leading to even greater sensitivity. Although a growing number of theoretical studies have been devoted to such higher-order degeneracies, their experimental demonstration in the optical domain has so far remained elusive. Here we report the observation of higher-order exceptional points in a coupled cavity arrangement—specifically, a ternary, parity-time-symmetric photonic laser molecule—with a carefully tailored gain-loss distribution. We study the system in the spectral domain and find that the frequency response associated with this system follows a cube-root dependence on induced perturbations in the refractive index. Our work paves the way for utilizing non-Hermitian degeneracies in fields including photonics, optomechanics, microwaves and atomic physics.
Time-Discrete Higher-Order ALE Formulations: Stability
Bonito, Andrea
2013-01-01
Arbitrary Lagrangian Eulerian (ALE) formulations deal with PDEs on deformable domains upon extending the domain velocity from the boundary into the bulk with the purpose of keeping mesh regularity. This arbitrary extension has no effect on the stability of the PDE but may influence that of a discrete scheme. We examine this critical issue for higher-order time stepping without space discretization. We propose time-discrete discontinuous Galerkin (dG) numerical schemes of any order for a time-dependent advection-diffusion-model problem in moving domains, and study their stability properties. The analysis hinges on the validity of the Reynold\\'s identity for dG. Exploiting the variational structure and assuming exact integration, we prove that our conservative and nonconservative dG schemes are equivalent and unconditionally stable. The same results remain true for piecewise polynomial ALE maps of any degree and suitable quadrature that guarantees the validity of the Reynold\\'s identity. This approach generalizes the so-called geometric conservation law to higher-order methods. We also prove that simpler Runge-Kutta-Radau methods of any order are conditionally stable, that is, subject to a mild ALE constraint on the time steps. Numerical experiments corroborate and complement our theoretical results. © 2013 Society for Industrial and Applied Mathematics.
Near integrability of kink lattice with higher order interactions
Jiang, Yun-Guo; Liu, Jia-Zhen; He, Song
2017-11-01
We make use of Manton’s analytical method to investigate the force between kinks and anti-kinks at large distances in 1+1 dimensional field theory. The related potential has infinite order corrections of exponential pattern, and the coefficients for each order are determined. These coefficients can also be obtained by solving the equation of the fluctuations around the vacuum. At the lowest order, the kink lattice represents the Toda lattice. With higher order correction terms, the kink lattice can represent one kind of generic Toda lattice. With only two sites, the kink lattice is classically integrable. If the number of sites of the lattice is larger than two, the kink lattice is not integrable but is a near integrable system. We make use of Flaschka’s variables to study the Lax pair of the kink lattice. These Flaschka’s variables have interesting algebraic relations and non-integrability can be manifested. We also discuss the higher Hamiltonians for the deformed open Toda lattice, which has a similar result to the ordinary deformed Toda. Supported by Shandong Provincial Natural Science Foundation (ZR2014AQ007), National Natural Science Foundation of China (11403015, U1531105), S. He is supported by Max-Planck fellowship in Germany and National Natural Science Foundation of China (11305235)
Compiler-Directed Transformation for Higher-Order Stencils
Energy Technology Data Exchange (ETDEWEB)
Basu, Protonu [Univ. of Utah, Salt Lake City, UT (United States); Hall, Mary [Univ. of Utah, Salt Lake City, UT (United States); Williams, Samuel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Straalen, Brian Van [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oliker, Leonid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Colella, Phillip [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2015-07-20
As the cost of data movement increasingly dominates performance, developers of finite-volume and finite-difference solutions for partial differential equations (PDEs) are exploring novel higher-order stencils that increase numerical accuracy and computational intensity. This paper describes a new compiler reordering transformation applied to stencil operators that performs partial sums in buffers, and reuses the partial sums in computing multiple results. This optimization has multiple effect son improving stencil performance that are particularly important to higher-order stencils: exploits data reuse, reduces floating-point operations, and exposes efficient SIMD parallelism to backend compilers. We study the benefit of this optimization in the context of Geometric Multigrid (GMG), a widely used method to solvePDEs, using four different Jacobi smoothers built from 7-, 13-, 27-and 125-point stencils. We quantify performance, speedup, andnumerical accuracy, and use the Roofline model to qualify our results. Ultimately, we obtain over 4× speedup on the smoothers themselves and up to a 3× speedup on the multigrid solver. Finally, we demonstrate that high-order multigrid solvers have the potential of reducing total data movement and energy by several orders of magnitude.
Massless and massive higher spins from anti-de Sitter space waveguide
Energy Technology Data Exchange (ETDEWEB)
Gwak, Seungho; Kim, Jaewon [School of Physics and Astronomy & Center for Theoretical Physics, Seoul National University,Seoul 08826 (Korea, Republic of); Rey, Soo-Jong [School of Physics and Astronomy & Center for Theoretical Physics, Seoul National University,Seoul 08826 (Korea, Republic of); Fields, Gravity & Strings, Center for Theoretical Physics of the Universe, Institute for Basic Sciences,Daejeon 34047 (Korea, Republic of)
2016-11-07
Understanding Higgs mechanism for higher-spin gauge fields is an outstanding open problem. We investigate this problem in the context of Kaluza-Klein compactification. Starting from a free massless higher-spin field in (d+2)-dimensional anti-de Sitter space and compactifying over a finite angular wedge, we obtain an infinite tower of heavy, light and massless higher-spin fields in (d+1)-dimensional anti-de Sitter space. All massive higher-spin fields are described gauge invariantly in terms of Stueckelberg fields. The spectrum depends on the boundary conditions imposed at both ends of the wedges. We observed that higher-derivative boundary condition is inevitable for spin greater than three. For some higher-derivative boundary conditions, equivalently, spectrum-dependent boundary conditions, we get a non-unitary representation of partially-massless higher-spin fields of varying depth. We present intuitive picture which higher-derivative boundary conditions yield non-unitary system in terms of boundary action. We argue that isotropic Lifshitz interfaces in O(N) Heisenberg magnet or O(N) Gross-Neveu model provides the holographic dual conformal field theory and propose experimental test of (inverse) Higgs mechanism for massive and partially massless higher-spin fields.
Massless and massive higher spins from anti-de Sitter space waveguide
Gwak, Seungho; Kim, Jaewon; Rey, Soo-Jong
2016-11-01
Understanding Higgs mechanism for higher-spin gauge fields is an outstanding open problem. We investigate this problem in the context of Kaluza-Klein compactification. Starting from a free massless higher-spin field in ( d + 2)-dimensional anti-de Sitter space and compactifying over a finite angular wedge, we obtain an infinite tower of heavy, light and massless higher-spin fields in ( d + 1)-dimensional anti-de Sitter space. All massive higher-spin fields are described gauge invariantly in terms of Stueckelberg fields. The spectrum depends on the boundary conditions imposed at both ends of the wedges. We observed that higher-derivative boundary condition is inevitable for spin greater than three. For some higher-derivative boundary conditions, equivalently, spectrum-dependent boundary conditions, we get a non-unitary representation of partially-massless higher-spin fields of varying depth. We present intuitive picture which higher-derivative boundary conditions yield non-unitary system in terms of boundary action. We argue that isotropic Lifshitz interfaces in O( N ) Heisenberg magnet or O( N ) Gross-Neveu model provides the holographic dual conformal field theory and propose experimental test of (inverse) Higgs mechanism for massive and partially massless higher-spin fields.
Ruling out Higher-Order Interference from Purity Principles
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Howard Barnum
2017-06-01
Full Text Available As first noted by Rafael Sorkin, there is a limit to quantum interference. The interference pattern formed in a multi-slit experiment is a function of the interference patterns formed between pairs of slits; there are no genuinely new features resulting from considering three slits instead of two. Sorkin has introduced a hierarchy of mathematically conceivable higher-order interference behaviours, where classical theory lies at the first level of this hierarchy and quantum theory theory at the second. Informally, the order in this hierarchy corresponds to the number of slits on which the interference pattern has an irreducible dependence. Many authors have wondered why quantum interference is limited to the second level of this hierarchy. Does the existence of higher-order interference violate some natural physical principle that we believe should be fundamental? In the current work we show that such principles can be found which limit interference behaviour to second-order, or “quantum-like”, interference, but that do not restrict us to the entire quantum formalism. We work within the operational framework of generalised probabilistic theories, and prove that any theory satisfying Causality, Purity Preservation, Pure Sharpness, and Purification—four principles that formalise the fundamental character of purity in nature—exhibits at most second-order interference. Hence these theories are, at least conceptually, very “close” to quantum theory. Along the way we show that systems in such theories correspond to Euclidean Jordan algebras. Hence, they are self-dual and, moreover, multi-slit experiments in such theories are described by pure projectors.
Radiation by solitons due to higher-order dispersion
DEFF Research Database (Denmark)
Karpman, V.I.
1993-01-01
in a simple and general way the radiation of KdV and NS, as well as other types. of solitons, is developed. From the WKB approach it follows that the soliton radiation is a result of a tunneling transformation of the non-linearly self-trapped wave into the free-propagating radiation.......We consider the Korteweg-de Vries (KdV) and nonlinear Schrodinger (NS) equations with higher-order derivative terms describing dispersive corrections. Conditions of existence of stationary and radiating solitons of the fifth-order KdV equation are obtained. An asymptotic time-dependent solution...... to the latter equation, describing the soliton radiation, is found. The radiation train may be in front as well as behind the soliton, depending on the sign of dispersion. The change rate of the soliton due to the radiation is calculated. A modification of the WKB method, that permits one to describe...
Higher-order conditioning is impaired by hippocampal lesions.
Gilboa, Asaf; Sekeres, Melanie; Moscovitch, Morris; Winocur, Gordon
2014-09-22
Behavior in the real world is rarely motivated by primary conditioned stimuli that have been directly associated with potent unconditioned reinforcers. Instead, motivation and choice behavior are driven by complex chains of higher-order associations that are only indirectly linked to intrinsic reward and often exert their influence outside awareness. Second-order conditioning (SOC) [1] is a basic associative-learning mechanism whereby stimuli acquire motivational salience by proxy, in the absence of primary incentives [2, 3]. Memory-systems theories consider first-order conditioning (FOC) and SOC to be prime examples of hippocampal-independent nondeclarative memory [4, 5]. Accordingly, neurobiological models of SOC focus almost exclusively on nondeclarative neural systems that support motivational salience and reward value. Transfer of value from a conditioned stimulus to a neutral stimulus is thought to require the basolateral amygdala [6, 7] and the ventral striatum [2, 3], but not the hippocampus. We developed a new paradigm to measure appetitive SOC of tones in rats. Hippocampal lesions severely impaired both acquisition and expression of SOC despite normal FOC. Unlike controls, rats with hippocampal lesions could not discriminate between positive and negative secondary conditioned tones, although they exhibited general familiarity with previously presented tones compared with new tones. Importantly, normal rats' behavior, in contrast to that of hippocampal groups, also revealed different confidence levels as indexed by effort, a central characteristic of hippocampal relational memory. The results indicate, contrary to current systems models, that representations of intrinsic relationships between reward value, stimulus identity, and motivation require hippocampal mediation when these relationships are of a higher order. Copyright © 2014 Elsevier Ltd. All rights reserved.
Programming real-time executives in higher order language
Foudriat, E. C.
1982-01-01
Methods by which real-time executive programs can be implemented in a higher order language are discussed, using HAL/S and Path Pascal languages as program examples. Techniques are presented by which noncyclic tasks can readily be incorporated into the executive system. Situations are shown where the executive system can fail to meet its task scheduling and yet be able to recover either by rephasing the clock or stacking the information for later processing. The concept of deadline processing is shown to enable more effective mixing of time and information synchronized systems.
Higher-order Brunnian structures and possible physical realizations
DEFF Research Database (Denmark)
A. Baas, Nils; V. Fedorov, D.; S. Jensen, A.
2014-01-01
We consider few-body bound state systems and provide precise definitions of Borromean and Brunnian systems. The initial concepts are more than a hundred years old and originated in mathematical knot-theory as purely geometric considerations. About thirty years ago they were generalized and applied...... to the binding of systems in nature. It now appears that recent generalization to higher order Brunnian structures may potentially be realized as laboratory made or naturally occurring systems. With the binding energy as measure, we discuss possibilities of physical realization in nuclei, cold atoms...
Solution of higher order boundary value problems by spline methods
Chaurasia, Anju; Srivastava, P. C.; Gupta, Yogesh
2017-10-01
Spline solution of Boundary Value Problems has received much attention in recent years. It has proven to be a powerful tool due to the ease of use and quality of results. This paper concerns with the survey of methods that try to approximate the solution of higher order BVPs using various spline functions. The purpose of this article is to thrash out the problems as well as conclusions, reached by the numerous authors in the related field. We critically assess many important relevant papers, published in reputed journals during last six years.
Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia.
Choi, Seung Kwon; Chang, Ji Woong
2016-02-01
To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.
Sirkis, James S. (Inventor); Sivanesan, Ponniah (Inventor); Venkat, Venki S. (Inventor)
2001-01-01
A Bragg grating sensor for measuring distributed strain and temperature at the same time comprises an optical fiber having a single mode operating wavelength region and below a cutoff wavelength of the fiber having a multimode operating wavelength region. A saturated, higher order Bragg grating having first and second order Bragg conditions is fabricated in the optical fiber. The first order of Bragg resonance wavelength of the Bragg grating is within the single mode operating wavelength region of the optical fiber and the second order of Bragg resonance wavelength is below the cutoff wavelength of the fiber within the multimode operating wavelength region. The reflectivities of the saturated Bragg grating at the first and second order Bragg conditions are less than two orders of magnitude of one another. In use, the first and second order Bragg conditions are simultaneously created in the sensor at the respective wavelengths and a signal from the sensor is demodulated with respect to each of the wavelengths corresponding to the first and second order Bragg conditions. Two Bragg conditions have different responsivities to strain and temperature, thus allowing two equations for axial strain and temperature to be found in terms of the measure shifts in the primary and second order Bragg wavelengths. This system of equations can be solved for strain and temperature.
Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers
Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.
2011-01-01
This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system.When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.
A Simplified Algorithm for Inverting Higher Order Diffusion Tensors
Directory of Open Access Journals (Sweden)
Laura Astola
2014-11-01
Full Text Available In Riemannian geometry, a distance function is determined by an inner product on the tangent space. In Riemann–Finsler geometry, this distance function can be determined by a norm. This gives more freedom on the form of the so-called indicatrix or the set of unit vectors. This has some interesting applications, e.g., in medical image analysis, especially in diffusion weighted imaging (DWI. An important application of DWI is in the inference of the local architecture of the tissue, typically consisting of thin elongated structures, such as axons or muscle fibers, by measuring the constrained diffusion of water within the tissue. From high angular resolution diffusion imaging (HARDI data, one can estimate the diffusion orientation distribution function (dODF, which indicates the relative diffusivity in all directions and can be represented by a spherical polynomial. We express this dODF as an equivalent spherical monomial (higher order tensor to directly generalize the (second order diffusion tensor approach. To enable efficient computation of Riemann–Finslerian quantities on diffusion weighted (DW-images, such as the metric/norm tensor, we present a simple and efficient algorithm to invert even order spherical monomials, which extends the familiar inversion of diffusion tensors, i.e., symmetric matrices.
Predictors of third and Higher order births in India
Directory of Open Access Journals (Sweden)
Payal Singh
2015-12-01
Full Text Available Background: Total fertility rate (TFR reflecting population growth is closely related to higher order parity progression. Many Indian states reached replacement level of TFR, but still states constituting nearly 40% population are with TFR ≥ 3. The predictors are the desire of son’s, poor contraceptives practices, younger age at marriage, child loss and shorter birth spacing. Objective: This analysis assessed the degree of relation of 3rd and higher order parity progression with the above mentioned predictors. Material and Methods: State/Union Territories wise proportions of women: progressing to ≥3 births, more sons desire, birth spacing <24 months, adopting modern contraception and median marriage age <18 years along with infant mortality rate (IMR were taken from NFHS-III report. Correlation matrix and stepwise forward multiple regression carried. Significance was seen at 5%. Results: Hindi speaking states constituting 38.92% nation population recorded TFR ≥3. Positive correlation of mothers progressing ≥ 3 births was highest (0.746 with those desiring more sons followed by IMR (0.445; while maximum negative correlation with those practicing modern contraceptives (-0.565 followed by median age at marriage (-0.391. Multiple regression analysis in order identified desire of more sons, practicing modern contraception and shorter birth spacing as the significant predictors and jointly explained 77.9% of the total variation with gain of 15.5% by adding modern contraceptive practice and 8.3% by adding shorter birth spacing. Conclusions: Desire of more sons appeared the most important predictor to progress ≥3 births that is governed by society culture and educational attainment, require attitudinal change. Further, mothers need motivation to practice both spacing and terminal methods once family is complete.
Higher-order phase transitions on financial markets
Kasprzak, A.; Kutner, R.; Perelló, J.; Masoliver, J.
2010-08-01
Statistical and thermodynamic properties of the anomalous multifractal structure of random interevent (or intertransaction) times were thoroughly studied by using the extended continuous-time random walk (CTRW) formalism of Montroll, Weiss, Scher, and Lax. Although this formalism is quite general (and can be applied to any interhuman communication with nontrivial priority), we consider it in the context of a financial market where heterogeneous agent activities can occur within a wide spectrum of time scales. As the main general consequence, we found (by additionally using the Saddle-Point Approximation) the scaling or power-dependent form of the partition function, Z(q'). It diverges for any negative scaling powers q' (which justifies the name anomalous) while for positive ones it shows the scaling with the general exponent τ(q'). This exponent is the nonanalytic (singular) or noninteger power of q', which is one of the pilar of higher-order phase transitions. In definition of the partition function we used the pausing-time distribution (PTD) as the central one, which takes the form of convolution (or superstatistics used, e.g. for describing turbulence as well as the financial market). Its integral kernel is given by the stretched exponential distribution (often used in disordered systems). This kernel extends both the exponential distribution assumed in the original version of the CTRW formalism (for description of the transient photocurrent measured in amorphous glassy material) as well as the Gaussian one sometimes used in this context (e.g. for diffusion of hydrogen in amorphous metals or for aging effects in glasses). Our most important finding is the third- and higher-order phase transitions, which can be roughly interpreted as transitions between the phase where high frequency trading is most visible and the phase defined by low frequency trading. The specific order of the phase transition directly depends upon the shape exponent α defining the stretched
Ducasse, Éric; Yaacoubi, Slah
2010-01-01
A tensor Hankel transform (THT) is defined for vector fields, such as displacement, and second-order tensor fields, such as stress or strain. The THT establishes a bijection between the real space and the wave-vector domain, and, remarkably, cannot be reduced to a scalar transform applied separately to each component. One of the advantages of this approach is that some standard elasticity problems can be concisely rewritten by applying this tensor integral transform coupled with an azimuthal Fourier series expansion. A simple and compact formulation of the boundary conditions is also achieved. Thanks to the THT, we obtain for each azimuthal wavenumber and each azimuthal direction exactly the same wave equation as for a standard 2D model of elastic wave propagation. Thus, waves similar to the standard plane P, SV and SH waves are naturally found. Lastly, the THT is used to calculate the ultrasonic field in an isotropic cylindrical leaky waveguide, the walls of which radiating into a surrounding elastic medium, by using a standard scattering approach.
Temporal mode selectivity by frequency conversion in second-order nonlinear optical waveguides
DEFF Research Database (Denmark)
Reddy, D. V.; Raymer, M. G.; McKinstrie, C. J.
2013-01-01
in a transparent optical network using temporally orthogonal waveforms to encode different channels. We model the process using coupled-mode equations appropriate for wave mixing in a uniform second-order nonlinear optical medium pumped by a strong laser pulse. We find Green functions describing the process......We explore theoretically the feasibility of using frequency conversion by sum- or difference-frequency generation, enabled by three-wave-mixing, for selectively multiplexing orthogonal input waveforms that overlap in time and frequency. Such a process would enable a drop device for use...
RNA Seeds Higher-Order Assembly of FUS Protein
Directory of Open Access Journals (Sweden)
Jacob C. Schwartz
2013-11-01
Full Text Available The abundant nuclear RNA binding protein FUS binds the C-terminal domain (CTD of RNA polymerase II in an RNA-dependent manner, affecting Ser2 phosphorylation and transcription. Here, we examine the mechanism of this process and find that RNA binding nucleates the formation of higher-order FUS ribonucleoprotein assemblies that bind the CTD. Both the low-complexity domain and the arginine-glycine rich domain of FUS contribute to assembly. The assemblies appear fibrous by electron microscopy and have characteristics of β zipper structures. These results support the emerging view that the pathologic protein aggregation seen in neurodegenerative diseases such as amyotrophic lateral sclerosis may occur via the exaggeration of functionally important assemblies of RNA binding proteins.
Recognition of higher order patterns in proteins: immunologic kernels.
Directory of Open Access Journals (Sweden)
Robert D Bremel
Full Text Available By applying analysis of the principal components of amino acid physical properties we predicted cathepsin cleavage sites, MHC binding affinity, and probability of B-cell epitope binding of peptides in tetanus toxin and in ten diverse additional proteins. Cross-correlation of these metrics, for peptides of all possible amino acid index positions, each evaluated in the context of a ±25 amino acid flanking region, indicated that there is a strongly repetitive pattern of short peptides of approximately thirty amino acids each bounded by cathepsin cleavage sites and each comprising B-cell linear epitopes, MHC-I and MHC-II binding peptides. Such "immunologic kernel" peptides comprise all signals necessary for adaptive immunologic cognition, response and recall. The patterns described indicate a higher order spatial integration that forms a symbolic logic coordinating the adaptive immune system.
Cognition with few neurons: higher-order learning in insects.
Giurfa, Martin
2013-05-01
Insects possess miniature brains but exhibit a sophisticated behavioral repertoire. Recent studies have reported the existence of unsuspected cognitive capabilities in various insect species that go beyond the traditionally studied framework of simple associative learning. Here, I focus on capabilities such as attentional modulation and concept learning and discuss their mechanistic bases. I analyze whether these behaviors, which appear particularly complex, can be explained on the basis of elemental associative learning and specific neural circuitries or, by contrast, require an explanatory level that goes beyond simple associative links. In doing this, I highlight experimental challenges and suggest future directions for investigating the neurobiology of higher-order learning in insects, with the goal of uncovering the basic neural architectures underlying cognitive processing. Copyright © 2013 Elsevier Ltd. All rights reserved.
Neutron scattering studies on chromatin higher-order structure
Energy Technology Data Exchange (ETDEWEB)
Graziano, V.; Gerchman, S.E.; Schneider, D.K.; Ramakrishnan, V. [Brookhaven National Laboratory, Upton, NY (United States)
1994-12-31
We have been engaged in studies of the structure and condensation of chromatin into the 30nm filament using small-angle neutron scattering. We have also used deuterated histone H1 to determine its location in the chromatin 30nm filament. Our studies indicate that chromatin condenses with increasing ionic strength to a limiting structure that has a mass per unit length of 6-7 nucleosomes/11 nm. They also show that the linker histone H1/H5 is located in the interior of the chromatin filament, in a position compatible with its binding to the inner face of the nucleosome. Analysis of the mass per unit length as a function of H5 stoichiometry suggests that 5-7 contiguous nucleosomes need to have H5 bound before a stable higher order structure can exist.
Nonlinear eigenvalue problems for higher order Lidstone boundary value problems
Directory of Open Access Journals (Sweden)
Paul Eloe
2000-01-01
Full Text Available In this paper, we consider the Lidstone boundary value problem $y^{(2m}(t = \\lambda a(tf(y(t, \\dots, y^{(2j}(t, \\dots y^{(2(m-1}(t, 0 0$ and $a$ is nonnegative. Growth conditions are imposed on $f$ and inequalities involving an associated Green's function are employed which enable us to apply a well-known cone theoretic fixed point theorem. This in turn yields a $\\lambda$ interval on which there exists a nontrivial solution in a cone for each $\\lambda$ in that interval. The methods of the paper are known. The emphasis here is that $f$ depends upon higher order derivatives. Applications are made to problems that exhibit superlinear or sublinear type growth.
Mixed Higher Order Variational Model for Image Recovery
Directory of Open Access Journals (Sweden)
Pengfei Liu
2014-01-01
Full Text Available A novel mixed higher order regularizer involving the first and second degree image derivatives is proposed in this paper. Using spectral decomposition, we reformulate the new regularizer as a weighted L1-L2 mixed norm of image derivatives. Due to the equivalent formulation of the proposed regularizer, an efficient fast projected gradient algorithm combined with monotone fast iterative shrinkage thresholding, called, FPG-MFISTA, is designed to solve the resulting variational image recovery problems under majorization-minimization framework. Finally, we demonstrate the effectiveness of the proposed regularization scheme by the experimental comparisons with total variation (TV scheme, nonlocal TV scheme, and current second degree methods. Specifically, the proposed approach achieves better results than related state-of-the-art methods in terms of peak signal to ratio (PSNR and restoration quality.
Higher-order Brunnian structures and possible physical realizations
Baas, N. A.; Fedorov, D. V.; Jensen, A. S.; Riisager, K.; Volosniev, A. G.; Zinner, N. T.
2014-03-01
We consider few-body bound state systems and provide precise definitions of Borromean and Brunnian systems. The initial concepts are more than a hundred years old and originated in mathematical knot-theory as purely geometric considerations. About thirty years ago they were generalized and applied to the binding of systems in nature. It now appears that recent generalization to higher-order Brunnian structures may potentially be realized as laboratory-made or naturally occurring systems. With the binding energy as measure, we discuss possibilities of physical realization in nuclei, cold atoms, and condensedmatter systems. Appearance is not excluded. However, both the form and the strengths of the interactions must be rather special. The most promising subfields for present searches would be in cold atoms because of external control of effective interactions, or perhaps in condensed-matter systems with nonlocal interactions. In nuclei, it would only be by sheer luck due to a lack of tunability.
Higher order corrections to asymptotic-de Sitter inflation
Mohsenzadeh, M.; Yusofi, E.
2017-08-01
Since trans-Planckian considerations can be associated with the re-definition of the initial vacuum, we investigate further the influence of trans-Planckian physics on the spectra produced by the initial quasi-de Sitter (dS) state during inflation. We use the asymptotic-dS mode to study the trans-Planckian correction of the power spectrum to the quasi-dS inflation. The obtained spectra consist of higher order corrections associated with the type of geometry and harmonic terms sensitive to the fluctuations of space-time (or gravitational waves) during inflation. As an important result, the amplitude of the power spectrum is dependent on the choice of c, i.e. the type of space-time in the period of inflation. Also, the results are always valid for any asymptotic dS space-time and particularly coincide with the conventional results for dS and flat space-time.
Methods and framework for visualizing higher-order finite elements.
Schroeder, William J; Bertel, François; Malaterre, Mathieu; Thompson, David; Pébay, Philippe P; O'Bara, Robert; Tendulkar, Saurabh
2006-01-01
The finite element method is an important, widely used numerical technique for solving partial differential equations. This technique utilizes basis functions for approximating the geometry and the variation of the solution field over finite regions, or elements, of the domain. These basis functions are generally formed by combinations of polynomials. In the past, the polynomial order of the basis has been low-typically of linear and quadratic order. However, in recent years so-called p and hp methods have been developed, which may elevate the order of the basis to arbitrary levels with the aim of accelerating the convergence of the numerical solution. The increasing complexity of numerical basis functions poses a significant challenge to visualization systems. In the past, such systems have been loosely coupled to simulation packages, exchanging data via file transfer, and internally reimplementing the basis functions in order to perform interpolation and implement visualization algorithms. However, as the basis functions become more complex and, in some cases, proprietary in nature, it becomes increasingly difficult if not impossible to reimplement them within the visualization system. Further, most visualization systems typically process linear primitives, in part to take advantage of graphics hardware and, in part, due to the inherent simplicity of the resulting algorithms. Thus, visualization of higher-order finite elements requires tessellating the basis to produce data compatible with existing visualization systems. In this paper, we describe adaptive methods that automatically tessellate complex finite element basis functions using a flexible and extensible software framework. These methods employ a recursive, edge-based subdivision algorithm driven by a set of error metrics including geometric error, solution error, and error in image space. Further, we describe advanced pretessellation techniques that guarantees capture of the critical points of the
Schizophrenia patients have higher-order language and extralinguistic impairments.
Pawełczyk, Agnieszka; Kotlicka-Antczak, Magdalena; Łojek, Emila; Ruszpel, Anna; Pawełczyk, Tomasz
2017-04-21
The extralinguistic and paralinguistic aspects of the language refer to higher-order language functions such as lexical-semantic processes, prosody, indirect speech acts or discourse comprehension and production. Studies suggest that these processes are mediated by the Right Hemisphere (RH) and there is also some evidence of RH dysfunctions in schizophrenia. The aim of the paper is to investigate the extralinguistic and paralinguistic processing mediated by Right Hemisphere in schizophrenia patients using a validated and standardized battery of tests. Two groups of participants were examined: a schizophrenia sample (40 participants) and a control group (39 participants). Extralinguistic and paralinguistic processing was assessed in all subjects by the Polish version of the Right Hemisphere Language Battery (RHLB-PL), which measures comprehension of implicit information, naming, understanding humor, inappropriate remarks and comments, explanation and understanding of metaphors, understanding emotional and language prosody and discourse understanding. Schizophrenia patients scored significantly lower than controls in subtests measuring comprehension of implicit information, interpretation of humor, explanation of metaphors, inappropriate remarks and comments, discernment of emotional and language prosody and comprehension of discourse. No differences were observed in naming, understanding metaphors or in processing visuo-spatial information. Extralinguistic and paralinguistic dysfunctions appear to be present in schizophrenia patients and they suggest that RH processing may be disturbed in that group of patients. As the disturbances of higher-order language processes mediated by the RH may cause serious impairments in the social communication of patients, it is worth evaluating them during clinical examination. Copyright © 2017 Elsevier B.V. All rights reserved.
Phantom Friedmann cosmologies and higher-order characteristics of expansion
Dabrowski, Mariusz P.; Stachowiak, Tomasz
2006-04-01
We discuss a more general class of phantom (p -1) matter. We show that many types of evolution which include both Big-Bang and Big-Rip singularities are admitted and give explicit examples. Among some interesting models, there exist non-singular oscillating (or “bounce”) cosmologies, which appear due to a competition between positive and negative pressure of variety of matter content. From the point of view of the current observations the most interesting cosmologies are the ones which start with a Big-Bang and terminate at a Big-Rip. A related consequence of having a possibility of two types of singularities is that there exists an unstable static universe approached by the two asymptotic models—one of them reaches Big-Bang, and another reaches Big-Rip. We also give explicit relations between density parameters Ω and the dynamical characteristics for these generalized phantom models, including higher-order observational characteristics such as jerk and “kerk.” Finally, we discuss the observational quantities such as luminosity distance, angular diameter, and source counts, both in series expansion and explicitly, for phantom models. Our series expansion formulas for the luminosity distance and the apparent magnitude go as far as to the fourth-order in redshift z term, which includes explicitly not only the jerk, but also the “kerk” (or “snap”) which may serve as an indicator of the curvature of the universe.
Higher Order Modes Excitation of Micro Cantilever Beams
Jaber, Nizar
2014-05-01
In this study, we present analytical and experimental investigation of electrically actuated micro cantilever based resonators. These devices are fabricated using polyimide and coated with chrome and gold layers from both sides. The cantilevers are highly curled up due to stress gradient, which is a common imperfection in surface micro machining. Using a laser Doppler vibrometer, we applied a noise signal to experimentally find the first four resonance frequencies. Then, using a data acquisition card, we swept the excitation frequency around the first four natural modes of vibrations. Theoretically, we derived a reduced order model using the Galerkin method to simulate the dynamics of the system. Extensive numerical analysis and computations were performed. The numerical analysis was able to provide good matching with experimental values of the resonance frequencies. Also, we proved the ability to excite higher order modes using partial electrodes with shapes that resemble the shape of the mode of interest. Such micro-resonators are shown to be promising for applications in mass and gas sensing.
Higher-order gravity and the classical equivalence principle
Accioly, Antonio; Herdy, Wallace
2017-11-01
As is well known, the deflection of any particle by a gravitational field within the context of Einstein’s general relativity — which is a geometrical theory — is, of course, nondispersive. Nevertheless, as we shall show in this paper, the mentioned result will change totally if the bending is analyzed — at the tree level — in the framework of higher-order gravity. Indeed, to first order, the deflection angle corresponding to the scattering of different quantum particles by the gravitational field mentioned above is not only spin dependent, it is also dispersive (energy-dependent). Consequently, it violates the classical equivalence principle (universality of free fall, or equality of inertial and gravitational masses) which is a nonlocal principle. However, contrary to popular belief, it is in agreement with the weak equivalence principle which is nothing but a statement about purely local effects. It is worthy of note that the weak equivalence principle encompasses the classical equivalence principle locally. We also show that the claim that there exists an incompatibility between quantum mechanics and the weak equivalence principle, is incorrect.
Fracture in a higher-order elastic continuum
Shi, M. X.; Huang, Y.; Hwang, K. C.
2000-12-01
We have obtained analytically the mode I and mode II full-field solutions for a semi-infinite crack in an infinite solid characterized by the higher-order elastic continuum theory. The theory is the limit of the strain gradient plasticity theory (Fleck, N.A., Hutchinson, J.W., 1997. Strain gradient plasticity. In: Hutchinson, J.W., Wu, T.Y. (Eds.), Advances in Applied Mechanics, vol. 33. Academic Press, New York, 295-361) with the plastic work hardening exponent n=1. It also represents the macroscopic behavior of cellular materials. The analytical solution shows the transition from remotely imposed classical K field to the asymptotic field near the crack tip over the internal material lengths associated with the stretch gradient and rotation gradient of deformation. It is established that the asymptotic crack tip fields have no domain of physical validity because the stress tractions have the incorrect sign within a zone on the order of internal material length l1 associated with the stretch gradient of deformation. This analytical full-field solution can be used as an important benchmark for the various finite elements developed for strain gradient plasticity.
Renormalizability in D -dimensional higher-order gravity
Accioly, Antonio; de Almeida, José; Brito, Gustavo P.; Correia, Gilson
2017-04-01
A simple expression for calculating the classical potential in D -dimensional gravitational models is obtained through a method based on the generating functional. The prescription is then used as a mathematical tool to probe the conjecture that renormalizable higher-order gravity models—which are, of course, nonunitary—are endowed with a classical potential that is nonsingular at the origin. It is also shown that the converse of this statement is not true, which implies that the finiteness of the classical potential at the origin is a necessary but not sufficient condition for the renormalizability of the model. The systems we have utilized to verify the conjecture were fourth- and sixth-order gravity models in D dimensions. A discussion about the polemic question related to the renormalizability of new massive gravity, which Oda claimed to be renormalizable in 2009 and which was shown to be nonrenormalizable by Muneyuki and Ohta three years later, is considered. We remark that the solution of this issue is straightforward if the aforementioned conjecture is employed. We point out that our analysis is restricted to local models in which the propagator has simple and real poles.
Emotion recognition from EEG using higher order crossings.
Petrantonakis, Panagiotis C; Hadjileontiadis, Leontios J
2010-03-01
Electroencephalogram (EEG)-based emotion recognition is a relatively new field in the affective computing area with challenging issues regarding the induction of the emotional states and the extraction of the features in order to achieve optimum classification performance. In this paper, a novel emotion evocation and EEG-based feature extraction technique is presented. In particular, the mirror neuron system concept was adapted to efficiently foster emotion induction by the process of imitation. In addition, higher order crossings (HOC) analysis was employed for the feature extraction scheme and a robust classification method, namely HOC-emotion classifier (HOC-EC), was implemented testing four different classifiers [quadratic discriminant analysis (QDA), k-nearest neighbor, Mahalanobis distance, and support vector machines (SVMs)], in order to accomplish efficient emotion recognition. Through a series of facial expression image projection, EEG data have been collected by 16 healthy subjects using only 3 EEG channels, namely Fp1, Fp2, and a bipolar channel of F3 and F4 positions according to 10-20 system. Two scenarios were examined using EEG data from a single-channel and from combined-channels, respectively. Compared with other feature extraction methods, HOC-EC appears to outperform them, achieving a 62.3% (using QDA) and 83.33% (using SVM) classification accuracy for the single-channel and combined-channel cases, respectively, differentiating among the six basic emotions, i.e., happiness, surprise, anger, fear, disgust, and sadness. As the emotion class-set reduces its dimension, the HOC-EC converges toward maximum classification rate (100% for five or less emotions), justifying the efficiency of the proposed approach. This could facilitate the integration of HOC-EC in human machine interfaces, such as pervasive healthcare systems, enhancing their affective character and providing information about the user's emotional status (e.g., identifying user's emotion
Higher-order gravity in higher dimensions: geometrical origins of four-dimensional cosmology?
Energy Technology Data Exchange (ETDEWEB)
Troisi, Antonio [Universita degli Studi di Salerno, Dipartimento di Fisica ' ' E.R. Caianiello' ' , Salerno (Italy)
2017-03-15
Determining the cosmological field equations is still very much debated and led to a wide discussion around different theoretical proposals. A suitable conceptual scheme could be represented by gravity models that naturally generalize Einstein theory like higher-order gravity theories and higher-dimensional ones. Both of these two different approaches allow one to define, at the effective level, Einstein field equations equipped with source-like energy-momentum tensors of geometrical origin. In this paper, the possibility is discussed to develop a five-dimensional fourth-order gravity model whose lower-dimensional reduction could provide an interpretation of cosmological four-dimensional matter-energy components. We describe the basic concepts of the model, the complete field equations formalism and the 5-D to 4-D reduction procedure. Five-dimensional f(R) field equations turn out to be equivalent, on the four-dimensional hypersurfaces orthogonal to the extra coordinate, to an Einstein-like cosmological model with three matter-energy tensors related with higher derivative and higher-dimensional counter-terms. By considering the gravity model with f(R) = f{sub 0}R{sup n} the possibility is investigated to obtain five-dimensional power law solutions. The effective four-dimensional picture and the behaviour of the geometrically induced sources are finally outlined in correspondence to simple cases of such higher-dimensional solutions. (orig.)
Delayed Higher-Order Optical Nonlinearities in Noble Gases
Tarazkar, Maryam; Romanov, Dmitri; Levis, Robert
2014-05-01
The role of higher-order Kerr effect (HOKE) in femtosecond laser filamentation is currently at the center of a controversy, as alleged crossover from positive to negative nonlinear refractive index at higher intensities was proposed to cause filament stabilization. Experimental evidence of HOKE crossover or lack thereof is being hotly debated. Motivated by this debate, we report the frequency-dependent nonlinear refractive index coefficients n2 and n4 for a series of atmospheric-pressure noble gases: helium, neon, argon, krypton, and xenon. The corresponding atomic hyperpolarizability coefficients are obtained via auxiliary static electric field approach developed on the basis of ab initio calculations implemented in Dalton program and performed at the CCSD level of theory with t-Aug-cc-PV5Z basis set. The n4 index is obtained using the relations between the degenerate six-wave mixing coefficient and some other frequency-dependent second hyperpolarizability coefficients, which can be calculated on the basis of n2via the auxiliary field approach. For all the investigated gases, the n4 indices are found to be positive over the wavelength range 300 nm-1500 nm. This result runs counter to the HOKE crossover hypothesis. The calculated n4 indices demonstrate considerable temporal dispersion, which progressively increases from helium to xenon. This feature implies delayed nonlinearity and calls for modifications in current theoretical models of filamentation process. We gratefully acknowledge financial support through AFOSR MURI Grant No. FA9550-10-1-0561.
Predicting perceptual learning from higher-order cortical processing.
Wang, Fang; Huang, Jing; Lv, Yaping; Ma, Xiaoli; Yang, Bin; Wang, Encong; Du, Boqi; Li, Wu; Song, Yan
2016-01-01
Visual perceptual learning has been shown to be highly specific to the retinotopic location and attributes of the trained stimulus. Recent psychophysical studies suggest that these specificities, which have been associated with early retinotopic visual cortex, may in fact not be inherent in perceptual learning and could be related to higher-order brain functions. Here we provide direct electrophysiological evidence in support of this proposition. In a series of event-related potential (ERP) experiments, we recorded high-density electroencephalography (EEG) from human adults over the course of learning in a texture discrimination task (TDT). The results consistently showed that the earliest C1 component (68-84ms), known to reflect V1 activity driven by feedforward inputs, was not modulated by learning regardless of whether the behavioral improvement is location specific or not. In contrast, two later posterior ERP components (posterior P1 and P160-350) over the occipital cortex and one anterior ERP component (anterior P160-350) over the prefrontal cortex were progressively modified day by day. Moreover, the change of the anterior component was closely correlated with improved behavioral performance on a daily basis. Consistent with recent psychophysical and imaging observations, our results indicate that perceptual learning can mainly involve changes in higher-level visual cortex as well as in the neural networks responsible for cognitive functions such as attention and decision making. Copyright © 2015 Elsevier Inc. All rights reserved.
A Compact Coplanar Waveguide (CPW)-Fed Zeroth-Order Resonant Filter for Bandpass Applications
Choudhary, Dilip Kumar; Chaudhary, Raghvendra Kumar
2017-07-01
A new CPW-fed bandpass filter based on zeroth order resonant (ZOR) technique is presented in this paper. Proposed filter structure is designed on a CPW single layer where via is not required, hence reduces fabrication complexity. The property of metamaterial of ZOR has been utilized to reduce the filter size. The proposed structure is symmetrically CPW-fed and contains tuning-fork stub, which connects patch to CPW ground plane. The metamaterial properties are characterized by plotting dispersion diagram of proposed structure. The experimental result of proposed filter design shows an insertion loss of 0.51 dB, return loss of 22.5 dB with fractional bandwidth 61.5 % at centre frequency 2.60 GHz. The size of the filter is 0.45 λg×0.36 λg (λg is the guided wavelength at centre frequency).
Separating higher-order nonlinearities in transient absorption microscopy
Wilson, Jesse W.; Anderson, Miguel; Park, Jong Kang; Fischer, Martin C.; Warren, Warren S.
2015-08-01
The transient absorption response of melanin is a promising optically-accessible biomarker for distinguishing malignant melanoma from benign pigmented lesions, as demonstrated by earlier experiments on thin sections from biopsied tissue. The technique has also been demonstrated in vivo, but the higher optical intensity required for detecting these signals from backscattered light introduces higher-order nonlinearities in the transient response of melanin. These components that are higher than linear with respect to the pump or the probe introduce intensity-dependent changes to the overall response that complicate data analysis. However, our data also suggest these nonlinearities might be advantageous to in vivo imaging, in that different types of melanins have different nonlinear responses. Therefore, methods to separate linear from nonlinear components in transient absorption measurements might provide additional information to aid in the diagnosis of melanoma. We will discuss numerical methods for analyzing the various nonlinear contributions to pump-probe signals, with the ultimate objective of real time analysis using digital signal processing techniques. To that end, we have replaced the lock-in amplifier in our pump-probe microscope with a high-speed data acquisition board, and reprogrammed the coprocessor field-programmable gate array (FPGA) to perform lock-in detection. The FPGA lock-in offers better performance than the commercial instrument, in terms of both signal to noise ratio and speed. In addition, the flexibility of the digital signal processing approach enables demodulation of more complicated waveforms, such as spread-spectrum sequences, which has the potential to accelerate microscopy methods that rely on slow relaxation phenomena, such as photo-thermal and phosphorescence lifetime imaging.
Higher-order-mode damper as beam-position monitors; Higher-Order-Mode Daempfer als Stahllagemonitore
Energy Technology Data Exchange (ETDEWEB)
Peschke, C.
2006-03-15
In the framework of this thesis a beam-position monitor was developed, which can only because of the signals from the HOM dampers of a linear-accelerator structure determine the beam position with high accuracy. For the unique determination of the beam position in the plane a procedure was developed, which uses the amplitudes and the start-phase difference between a dipole mode and a higher monopole mode. In order tocheck the suitability of the present SBLC-HOM damper as beam position monitor three-dimensional numerical field calculations in the frequency and time range and measurements on the damper cell were performed. For the measurements without beam a beam simulator was constructed, which allows computer-driven measurements with variable depositions of the simulated beam with a resolution of 1.23 {mu}m. Because the complete 6 m long, 180-cell accelerator structure was not available for measurements and could also with the available computers not be three-dimensionally simulated simulated, a one-dimensional equivalent-circuit based model of the multi-cell was studied. The equivalent circuits with 879 concentrated components regards the detuning from cell to cell, the cell losses, the damper losses, and the beam excitation in dependence on the deposition. the measurements and simulations let a resolution of the ready beam-position monitor on the 180-cell in the order of magnitude of 1-10 {mu}m and a relative accuracy smaller 6.2% be expected.
Corneal Higher-Order Aberrations in Infectious Keratitis.
Shimizu, Eisuke; Yamaguchi, Takefumi; Yagi-Yaguchi, Yukari; Dogru, Murat; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun
2017-03-01
To characterize the corneal higher-order aberrations (HOAs) in eyes with Acanthamoeba keratitis (AK), bacterial keratitis (BK), and fungal keratitis (FK). Retrospective consecutive case series. This retrospective study includes 18 normal subjects and 63 eyes of 62 consecutive patients with corneal scarring due to AK (20 eyes), BK (35 eyes), and FK (8 eyes) from 2010 to 2016. HOAs of the anterior and posterior surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. Corneal HOA patterns were assigned on the basis of corneal topography maps. Corneal opacity grading was assigned on the basis of slit-lamp examinations. We evaluated corneal HOAs, corneal opacity grading, and their correlation with visual acuity. HOAs of the total cornea within a 4-mm diameter were significantly larger in eyes with infectious keratitis (AK, 1.15 ± 2.06 μm; BK, 0.91 ± 0.88 μm; FK, 1.39 ± 1.46 μm) compared with normal controls (0.09 ± 0.01 μm, all, P keratitis were associated with poorer visual acuity values. Asymmetric pattern was the most common topographic pattern in infectious keratitis. Copyright © 2016 Elsevier Inc. All rights reserved.
Degree of musical expertise modulates higher order brain functioning.
Oechslin, Mathias S; Van De Ville, Dimitri; Lazeyras, François; Hauert, Claude-Alain; James, Clara E
2013-09-01
Using functional magnetic resonance imaging, we show for the first time that levels of musical expertise stepwise modulate higher order brain functioning. This suggests that degree of training intensity drives such cerebral plasticity. Participants (non-musicians, amateurs, and expert musicians) listened to a comprehensive set of specifically composed string quartets with hierarchically manipulated endings. In particular, we implemented 2 irregularities at musical closure that differed in salience but were both within the tonality of the piece (in-key). Behavioral sensitivity scores (d') of both transgressions perfectly separated participants according to their level of musical expertise. By contrasting brain responses to harmonic transgressions against regular endings, functional brain imaging data showed compelling evidence for stepwise modulation of brain responses by both violation strength and expertise level in a fronto-temporal network hosting universal functions of working memory and attention. Additional independent testing evidenced an advantage in visual working memory for the professionals, which could be predicted by musical training intensity. The here introduced findings of brain plasticity demonstrate the progressive impact of musical training on cognitive brain functions that may manifest well beyond the field of music processing.
Higher-order graph wavelets and sparsity on circulant graphs
Kotzagiannidis, Madeleine S.; Dragotti, Pier Luigi
2015-08-01
The notion of a graph wavelet gives rise to more advanced processing of data on graphs due to its ability to operate in a localized manner, across newly arising data-dependency structures, with respect to the graph signal and underlying graph structure, thereby taking into consideration the inherent geometry of the data. In this work, we tackle the problem of creating graph wavelet filterbanks on circulant graphs for a sparse representation of certain classes of graph signals. The underlying graph can hereby be data-driven as well as fixed, for applications including image processing and social network theory, whereby clusters can be modelled as circulant graphs, respectively. We present a set of novel graph wavelet filter-bank constructions, which annihilate higher-order polynomial graph signals (up to a border effect) defined on the vertices of undirected, circulant graphs, and are localised in the vertex domain. We give preliminary results on their performance for non-linear graph signal approximation and denoising. Furthermore, we provide extensions to our previously developed segmentation-inspired graph wavelet framework for non-linear image approximation, by incorporating notions of smoothness and vanishing moments, which further improve performance compared to traditional methods.
A general higher-order remap algorithm for ALE calculations
Energy Technology Data Exchange (ETDEWEB)
Chiravalle, Vincent P [Los Alamos National Laboratory
2011-01-05
A numerical technique for solving the equations of fluid dynamics with arbitrary mesh motion is presented. The three phases of the Arbitrary Lagrangian Eulerian (ALE) methodology are outlined: the Lagrangian phase, grid relaxation phase and remap phase. The Lagrangian phase follows a well known approach from the HEMP code; in addition the strain rate andflow divergence are calculated in a consistent manner according to Margolin. A donor cell method from the SALE code forms the basis of the remap step, but unlike SALE a higher order correction based on monotone gradients is also added to the remap. Four test problems were explored to evaluate the fidelity of these numerical techniques, as implemented in a simple test code, written in the C programming language, called Cercion. Novel cell-centered data structures are used in Cercion to reduce the complexity of the programming and maximize the efficiency of memory usage. The locations of the shock and contact discontinuity in the Riemann shock tube problem are well captured. Cercion demonstrates a high degree of symmetry when calculating the Sedov blast wave solution, with a peak density at the shock front that is similar to the value determined by the RAGE code. For a flyer plate test problem both Cercion and FLAG give virtually the same velocity temporal profile at the target-vacuum interface. When calculating a cylindrical implosion of a steel shell, Cercion and FLAG agree well and the Cercion results are insensitive to the use of ALE.
Higher-order scene statistics of breast images
Abbey, Craig K.; Sohl-Dickstein, Jascha N.; Olshausen, Bruno A.; Eckstein, Miguel P.; Boone, John M.
2009-02-01
Researchers studying human and computer vision have found description and construction of these systems greatly aided by analysis of the statistical properties of naturally occurring scenes. More specifically, it has been found that receptive fields with directional selectivity and bandwidth properties similar to mammalian visual systems are more closely matched to the statistics of natural scenes. It is argued that this allows for sparse representation of the independent components of natural images [Olshausen and Field, Nature, 1996]. These theories have important implications for medical image perception. For example, will a system that is designed to represent the independent components of natural scenes, where objects occlude one another and illumination is typically reflected, be appropriate for X-ray imaging, where features superimpose on one another and illumination is transmissive? In this research we begin to examine these issues by evaluating higher-order statistical properties of breast images from X-ray projection mammography (PM) and dedicated breast computed tomography (bCT). We evaluate kurtosis in responses of octave bandwidth Gabor filters applied to PM and to coronal slices of bCT scans. We find that kurtosis in PM rises and quickly saturates for filter center frequencies with an average value above 0.95. By contrast, kurtosis in bCT peaks near 0.20 cyc/mm with kurtosis of approximately 2. Our findings suggest that the human visual system may be tuned to represent breast tissue more effectively in bCT over a specific range of spatial frequencies.
Multilinear Discriminant Analysis for Higher-Order Tensor Data Classification.
Li, Qun; Schonfeld, Dan
2014-12-01
In the past decade, great efforts have been made to extend linear discriminant analysis for higher-order data classification, generally referred to as multilinear discriminant analysis (MDA). Existing examples include general tensor discriminant analysis (GTDA) and discriminant analysis with tensor representation (DATER). Both the two methods attempt to resolve the problem of tensor mode dependency by iterative approximation. GTDA is known to be the first MDA method that converges over iterations. However, its performance relies highly on the tuning of the parameter in the scatter difference criterion. Although DATER usually results in better classification performance, it does not converge, yet the number of iterations executed has a direct impact on DATER's performance. In this paper, we propose a closed-form solution to the scatter difference objective in GTDA, namely, direct GTDA (DGTDA) which also gets rid of parameter tuning. We demonstrate that DGTDA outperforms GTDA in terms of both efficiency and accuracy. In addition, we propose constrained multilinear discriminant analysis (CMDA) that learns the optimal tensor subspace by iteratively maximizing the scatter ratio criterion. We prove both theoretically and experimentally that the value of the scatter ratio criterion in CMDA approaches its extreme value, if it exists, with bounded error, leading to superior and more stable performance in comparison to DATER.
Higher-order web link analysis using multilinear algebra.
Energy Technology Data Exchange (ETDEWEB)
Kenny, Joseph P.; Bader, Brett William (Sandia National Laboratories, Albuquerque, NM); Kolda, Tamara Gibson
2005-07-01
Linear algebra is a powerful and proven tool in web search. Techniques, such as the PageRank algorithm of Brin and Page and the HITS algorithm of Kleinberg, score web pages based on the principal eigenvector (or singular vector) of a particular non-negative matrix that captures the hyperlink structure of the web graph. We propose and test a new methodology that uses multilinear algebra to elicit more information from a higher-order representation of the hyperlink graph. We start by labeling the edges in our graph with the anchor text of the hyperlinks so that the associated linear algebra representation is a sparse, three-way tensor. The first two dimensions of the tensor represent the web pages while the third dimension adds the anchor text. We then use the rank-1 factors of a multilinear PARAFAC tensor decomposition, which are akin to singular vectors of the SVD, to automatically identify topics in the collection along with the associated authoritative web pages.
Positive solutions for higher order singular p-Laplacian boundary ...
Indian Academy of Sciences (India)
This paper investigates 2 m − t h ( m ≥ 2 ) order singular -Laplacian boundary value problems, and obtains the necessary and sufficient conditions for existence of positive solutions for sublinear 2-th order singular -Laplacian BVPs on closed interval.
Shukla, Divya; Dungsungnoen, Aj Pattaradanai
2016-01-01
Higher order thinking skills (HOTS) has portrayed immense industry demand and the major goal of educational institution in imparting education is to inculcate higher order thinking skills. This compiles and mandate the institutions and instructor to develop the higher order thinking skills among students in order to prepare them for effective…
Nonlinear acoustics in higher-order approximation: Comment.
Mitri, Farid G
2010-08-01
Some useful expressions for the second- and third-order equations for harmonic generation of infinite plane acoustic waves in a nonlinear non-viscous fluid are corrected. The concern addressed in the present comment is to point out some typographical errors in the first-order velocity and pressure expressions intervening in the calculation of the secondorder nonlinear equations, as well as a miscalculation of the axial component of the third-order Lighthill tensor term and the resulting third-order velocity and pressure equations presented in that paper.
Initial Semantics for higher-order typed syntax in Coq
Directory of Open Access Journals (Sweden)
Benedikt Ahrens
2011-01-01
Full Text Available Initial Semantics aims at characterizing the syntax associated to a signature as the initial object of some category. We present an initial semantics result for typed higher-order syntax together with its formalization in the Coq proof assistant. The main theorem was first proved on paper in the second author’s PhD thesis in 2010, and verified formally shortly afterwards.To a simply–typed binding signature S over a fixed set T of object types we associate a category called the category of representations of S. We show that this category has an initial object Sigma(S, i.e. an object Sigma(S from which there is precisely one morphism i_R : Sigma(S -> R to any object R of this category. From its construction it will be clear that the object Sigma(S merits the name abstract syntax associated to S: it is given by an inductive set – parametrized by a set of free variables and dependent on object types – the type of whose constructors are each given by the arities of the signature S.Our theorem is implemented and proved correct in the proof assistant Coq through heavy use of dependent types. The approach through monads gives rise to an implementation of syntax where both terms and variables are intrinsically typed, i.e. where the object types are rejected in the meta–level types. Terms are implemented as a Coq data type – which play the role of sets – dependent on an object type as well as on a type family of free variables.This article is to be seen as a research article rather than about the formalization of a classical mathematical result. The nature of our theorem – involving lengthy, technical proofs and complicated algebraic structures – makes it particularly interesting for formal verification. Our goal is to promote the use of computer theorem provers as research tools, and, accordingly, a new way of publishing mathematical results: a parallel description of a theorem and its formalization should allow the verification of
Proposed higher order continuum-based models for an elastic ...
African Journals Online (AJOL)
The resulting differential equations are similar in form and order to a high-order model developed earlier by Reissner based on a number of simplifying assumptions, but with different coefficients dependant on Poisson ratio. With the help of appropriately selected mechanical models, it has been shown that all of the new ...
High power, higher order ultrafast hollow Gaussian beams
Apurv Chaitanya, N.; Amrit Chaitanya, Banerji, J.; Samanta, G. K.
2017-05-01
We report on linear and nonlinear generation of ultrafast hollow Gaussian beams (HGBs). Using only two spiral phase plates (SPPs) having phase variation corresponding to vortex orders, l = 1 and 2, and an experimental scheme, we have generated high power, ultrafast HGBs of orders up to 3 at 1064 nm. Based on single-pass, frequency doubling of the HGBs in a 5 mm long, MgO doped, periodically poled LiNbO3 (MgO:PPLN) crystal, we have produced HGBs of average output power in excess of 250 mW at 532 nm and order as high as 6. Experimentally, we verified that the frequency doubled HGBs have orders twice those of the pump HGBs. Like the Gaussian beams, the HGBs of all orders have an optimum focusing condition for the highest conversion efficiency. On the contrary to previous reports, we observed that the propagation of the vortex beam of order, l, through a SPP corresponding to the vortex order of, -l, results in HGBs of the same order, | l | .
A Matrix Approach for General Higher Order Linear Recurrences
2011-01-01
properties of linear recurrences (such as the well-known Fibonacci and Pell sequences). In [2], Er defined k linear recurring sequences of order at...the nth term of the ith generalized order-k Fibonacci sequence. Communicated by Lee See Keong. Received: March 26, 2009; Revised: August 28, 2009...Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject
Upgrading the Marketing Curriculum: The Integration of Higher-Order Skills. A Perspective.
Schoettinger, Nancy L.
1985-01-01
Discusses the support for higher-order skills in the secondary school and vocational curricula, the need for higher-order skills in the marketing curriculum, methods of teaching higher-order skills, and implications for teacher education. (CT)
Higher-order diagrammatic vibrational coupled-cluster theory.
Faucheaux, Jacob A; Hirata, So
2015-10-07
Diagrammatically size-consistent and basis-set-free vibrational coupled-cluster (XVCC) theory for both zero-point energies and transition frequencies of a molecule, the latter through the equation-of-motion (EOM) formalism, is defined for an nth-order Taylor-series potential energy surface (PES). Quantum-field-theoretical tools (the rules of normal-ordered second quantization and Feynman-Goldstone diagrams) for deriving their working equations are established. The equations of XVCC and EOM-XVCC including up to the mth-order excitation operators are derived and implemented with the aid of computer algebra in the range of 1 ≤ m ≤ 8. Algorithm optimizations known as strength reduction, intermediate reuse, and factorization are carried out before code generation, reducing the cost scaling of the mth-order XVCC and EOM-XVCC in an nth-order Taylor-series PES (m ≥ n) to the optimal value of O(N(m+⌊n/2⌋)), where N is the number of modes. The calculated zero-point energies and frequencies of fundamentals, overtones, and combinations as well as Fermi-resonant modes display rapid and nearly monotonic convergence with m towards the exact values for the PES. The theory with the same excitation rank as the truncation order of the Taylor-series PES (m = n) seems to strike the best cost-accuracy balance, achieving the accuracy of a few tenths of cm(-1) for transitions involving (m - 3) modes and of a few cm(-1) for those involving (m - 2) modes. The relationships between XVCC and the vibrational coupled-cluster theories of Prasad and coworkers and of Christiansen and coworkers as well as the size-extensive vibrational self-consistent-field and many-body perturbation theories are also elucidated.
Higher-order soft corrections to squark hadro-production
Energy Technology Data Exchange (ETDEWEB)
Langenfeld, U.; Moch, S.
2009-01-15
We present new predictions for the total cross section of squark pair-production at Tevatron and LHC through next-to-next-to-leading order within the Minimal Supersymmetric Standard Model. The results are based on the numerically dominant soft corrections. They are exact in all logarithmically enhanced terms near threshold, include the Coulomb corrections at two loops and exact scale dependence. We translate the increased total cross section at next-to-next-to-leading order into improved exclusion limits for squark masses and we investigate the scale dependence as well as the sensitivity on the parton luminosity. (orig.)
The Complexity of Model Checking Higher-Order Fixpoint Logic
DEFF Research Database (Denmark)
Axelsson, Roland; Lange, Martin; Somla, Rafal
2007-01-01
provides complexity results for its model checking problem. In particular we consider its fragments HFLk,m which are formed using types of bounded order k and arity m only. We establish k-ExpTime-completeness for model checking each HFLk,m fragment. For the upper bound we reduce the problem to the problem...
Higher-order semiclassical energy expansions for potentials with ...
Indian Academy of Sciences (India)
Detailed studies were carried out on 1-D systems such as xN (N even) to obtain analytic eigenenergy expansions using WKB methods [6]. For some of these potentials WKB series were summed to all orders to obtain the exact solution [7]. In this paper, we analyse 1-D system |x|α. (α-real) for which we are able to obtain.
Demand-Driven Higher-Order Fixpoint Iteration
DEFF Research Database (Denmark)
Rosendahl, Mads
-order functions is to establish a notion of {\\em neededness} so as to restrict the iteration to those parts of the function that may influence the result. This is here done through a uniform extension of the domain of values with need information. The result is an iteration strategy which will terminate if base...
Encouraging Student Autonomy through Higher Order Thinking Skills
Smith, Victoria D.; Darvas, Janet W.
2017-01-01
This article discusses how to empower students to work, think, and act independently in the higher education setting. Inspiring students to progress through the stages of Bloom's Taxonomy emboldens them to discover intrinsic motivation and self-regulated learning. This article defines and focuses on the importance of teaching intrinsic motivation…
Higher-Order Semi-Implicit Projection Methods
Energy Technology Data Exchange (ETDEWEB)
Minion, M L
2001-09-06
A semi-implicit form of the method of spectral deferred corrections is applied to the solution of the incompressible Navier-Stokes equations. A methodology for constructing semi-implicit projection methods with arbitrarily high order of temporal accuracy in both the velocity and pressure is presented. Three variations of projection methods are discussed which differ in the manner in which the auxiliary velocity and the pressure are calculated. The presentation will make clear that project methods in general need not be viewed as fractional step methods as is often the practice. Two simple numerical examples re used to demonstrate fourth-order accuracy in time for an implementation of each variation of projection method.
Higher-Order Hamiltonian Model for Unidirectional Water Waves
Bona, J. L.; Carvajal, X.; Panthee, M.; Scialom, M.
2017-10-01
Formally second-order correct, mathematical descriptions of long-crested water waves propagating mainly in one direction are derived. These equations are analogous to the first-order approximations of KdV- or BBM-type. The advantage of these more complex equations is that their solutions corresponding to physically relevant initial perturbations of the rest state may be accurate on a much longer timescale. The initial value problem for the class of equations that emerges from our derivation is then considered. A local well-posedness theory is straightforwardly established by a contraction mapping argument. A subclass of these equations possess a special Hamiltonian structure that implies the local theory can be continued indefinitely.
Machine learning using a higher order correlation network
Energy Technology Data Exchange (ETDEWEB)
Lee, Y.C.; Doolen, G.; Chen, H.H.; Sun, G.Z.; Maxwell, T.; Lee, H.Y.
1986-01-01
A high-order correlation tensor formalism for neural networks is described. The model can simulate auto associative, heteroassociative, as well as multiassociative memory. For the autoassociative model, simulation results show a drastic increase in the memory capacity and speed over that of the standard Hopfield-like correlation matrix methods. The possibility of using multiassociative memory for a learning universal inference network is also discussed. 9 refs., 5 figs.
A Language for Higher-Order Explanation-Based Learning
1992-01-01
Fibonacci specification is formal since it is expressed in a (po- tentially) formal language. Languages for formal specification are generally characterized...solved in order to establish instances of G’s consequent D. Operationally, however, we need solve G only once, universally generalize , and then assume...But this is, of course, the whole purpose of rule: to focus search by making use of a selected consequence (VX’ Vy. crxyODx) of the general assumption
Stability of embedded solitons in higher-order NLS equations
Energy Technology Data Exchange (ETDEWEB)
Pal, Debabrata; Ali, Sk Golam; Talukdar, B, E-mail: binoy123@bsnl.in [Department of Physics, Visva-Bharati University, Santiniketan 731235 (India)
2011-02-15
We consider two models for femtosecond pulse propagation through optical fibers. The first one involves a nonlinear Schroedinger (NLS) equation with a perturbing term arising due to third-order dispersion in the medium, whereas the second one incorporates two additional effects-self-steepening (SS) and stimulated Raman scattering (SRS)-that have their physical origin in molecular vibration. We make use of the theory of Espinosa-Ceron et al (2003 Phys. Scr. 67 314) to analytically demonstrate that the third-order NLS equation involving terms due to SS and SRS obeys the radiation inhibition condition and thereby supports exponentially localized solitons. On the other hand, the purely third-order NLS equation invalidates the condition for radiation inhibition and its traveling wave solution shows oscillatory behavior due to the emission of radiation. We verify both these conclusions by numerical simulation and conclude that the effects of SS and SRS could be judiciously manipulated for the unattenuated propagation of femtosecond pulses through fibers.
Durán-Sindreu, Miguel; Vélez, Paris; Bonache, Jordi; Martín, Ferran
2011-06-01
In this paper, it is demonstrated that transmission lines loaded with a combination of open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs) are useful for the design of high-order band pass filters subjected to standard responses. Specifically, we present a 7-pole Chebyshev band pass filter in coplanar waveguide technology. The device is compact and filter performance is good, including a wide stopband response. With this work, we extend our previous work on the applications of OSRR- and OCSRR-loaded lines to the design of highly selective filters.
Higher-order predictions for supersymmetric particle decays
Energy Technology Data Exchange (ETDEWEB)
Landwehr, Ananda Demian Patrick
2012-06-12
We analyze particle decays including radiative corrections at the next-to-leading order (NLO) within the Minimal Supersymmetric Standard Model (MSSM). If the MSSM is realized at the TeV scale, squark and gluino production and decays yield relevant rates at the LHC. Hence, in the first part of this thesis, we compute decay widths including QCD and electroweak NLO corrections to squark and gluino decays. Furthermore, the Higgs sector of the MSSM is enhanced compared to the one of the Standard Model. Thus, the additional Higgs bosons decay also into supersymmetric particles. These decays and the according NLO corrections are analyzed in the second part of this thesis. The calculations are performed within a common renormalization framework and numerically evaluated in specific benchmark scenarios.
Higher-order hybrid stress triangular Mindlin plate element
Li, Tan; Ma, Xu; Xili, Jing; Chen, Wanji
2016-12-01
A 6-node triangular hybrid stress element is presented for Mindlin plate in this paper. The proposed element, denoted by TH6-27β, can pass both the zero shear stress patch test and the non-zero constant shear stress enhanced patch test and, it can be employed to analyze very thin plate. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is used successfully to derive the displacement interpolation along each side of the element. According to the equilibrium equations, an appropriate stress approximation is rationally obtained. The assumed stress field is modified by using 27β instead of 15β to improve the accuracy. Numerical results show that the element is free of shear locking, and reliable for thick and thin plates. Moreover, it has no spurious zero energy modes and with geometric invariance (coordinate invariance, node sequencing independence).
Polarization and visibility of higher-order rainbows.
Können, Gunther P
2015-02-01
The degree of polarization of rainbows of order k with k≥3 is bounded in the interval [75%, 78%], where 75% is the limit for k→∞. A polarization filter can improve the signal-to-background ratio of the third and fourth rainbows by a factor of 2, which may lift their visibilities in natural circumstances above the threshold of human visual perception. Under optimal circumstances, the latter may be true for the recently photographed green fingerprint of the fifth rainbow, even without the aid of a polarization filter. The prospects for observing the sixth rainbow are unclear. There exists a possibility that the signal of the natural seventh rainbow (appearing at 64° from the Sun) may be separated from its background if photographed under perfect conditions through a polarization filter.
Higher-order photon bunching in a semiconductor microcavity
DEFF Research Database (Denmark)
Assmann, M.; Veit, F.; Bayer, M.
2009-01-01
Quantum mechanically indistinguishable particles such as photons may show collective behavior. Therefore, an appropriate description of a light field must consider the properties of an assembly of photons instead of independent particles. We have studied multiphoton correlations up to fourth order...... in the single-mode emission of a semiconductor microcavity in the weak and strong coupling regimes. The counting statistics of single photons were recorded with picosecond time resolution, allowing quantitative measurement of the few-photon bunching inside light pulses. Our results show bunching behavior...... in the strong coupling case, which vanishes in the weak coupling regime as the cavity starts lasing. In particular, we verify the n factorial prediction for the zero-delay correlation function of n thermal light photons....
Reduction of background by higher order statistics with NMIS
Energy Technology Data Exchange (ETDEWEB)
Mattingly, jk; Mullens, ja; Mihalczo, jt
2000-07-11
Measurements that accumulate the rate of real coincidence between multiplets of detection events (groupings of arbitrary order, e.g., one event, two events, three events, etc.) can yield spurious results if background events arise from processes (e.g., spontaneous fission or neutron spallation) that themselves produce correlated multiplets. This is particularly true if this background varies significantly over time or from one location to another, as it often does in operating facilities, i.e., those not specifically designed to support experimental radiation measurements but that instead rely upon the support of precise radiation measurements for, e.g., NMC and A. In particular, both the quantity and location of radioactive material in weapons facilities changes frequently and unpredictably, and so the background due to the presence (or absence) of this material is completely out of the control of the radiation measurement analyst. Furthermore, numerous Nuclear Materials Identification System (NMIS) measurements have revealed that background often contains mutually correlated events even in the complete absence of material (e.g., {sup 240}Pu) with a significant spontaneous fission rate. The technique subsequently described removes the effects of such self-correlated background from active NMIS measurements. It could be adapted to other active radiation measurements.
Average gluon and quark jet multiplicities at higher orders
Energy Technology Data Exchange (ETDEWEB)
Bolzoni, Paolo; Kniehl, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kotikov, Anatoly V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics
2013-05-15
We develop a new formalism for computing and including both the perturbative and nonperturbative QCD contributions to the scale evolution of average gluon and quark jet multiplicities. The new method is motivated by recent progress in timelike small-x resummation obtained in the MS factorization scheme. We obtain next-to-next-to-leading-logarithmic (NNLL) resummed expressions, which represent generalizations of previous analytic results. Our expressions depend on two nonperturbative parameters with clear and simple physical interpretations. A global fit of these two quantities to all available experimental data sets that are compatible with regard to the jet algorithms demonstrates by its goodness how our results solve a longstanding problem of QCD. We show that the statistical and theoretical uncertainties both do not exceed 5% for scales above 10 GeV. We finally propose to use the jet multiplicity data as a new way to extract the strong-coupling constant. Including all the available theoretical input within our approach, we obtain {alpha}{sub s}{sup (5)}(M{sub Z})=0.1199{+-}0.0026 in the MS scheme in an approximation equivalent to next-to-next-to-leading order enhanced by the resummations of ln(x) terms through the NNLL level and of ln Q{sup 2} terms by the renormalization group, in excellent agreement with the present world average.
Analysis of oversized sliding waveguide by mode matching and multi-mode network theory
Energy Technology Data Exchange (ETDEWEB)
Ohkubo, K.; Kubo, S.; Idei, H.; Shimozuma, T.; Yoshimura, Y.; Sato, M.; Takita, Y. [National Inst. for Fusion Science, Toki, Gifu (Japan); Leuterer, F. [Max-Planck Institut fuer Plasmaphysik, Garching (Germany)
2000-12-01
Transmission and reflection coefficients of HE{sub 11} hybrid modes in the sliding waveguide are discussed on the basis of mode matching method and multi-mode network theory. The sliding waveguide is composed of the corrugated waveguide with 88.9 mm{phi} and the smooth-wall waveguide with 110 mm{phi} in inner diameter. It is confirmed that the decrease in power of <0.2% at 84 GHz is obtained for 2 cm in gap of the sliding waveguide. At the sliding length near multi-half-wavelength in vacuum, transmission and reflection powers in the sliding waveguide change slightly, because the very small amount of standing wave of higher-order TE or TM modes is produced resonantly. (author)
Higher order QCD corrections in exclusive charmless B decays
Energy Technology Data Exchange (ETDEWEB)
Bell, G.
2006-10-15
We discuss exclusive charmless B decays within the Standard Model of particle physics. These decays play a central role in the on-going process to constrain the parameters of the CKM matrix and to clarify the nature of CP violation. In order to exploit the rich source of data that is currently being collected at the experiments, a systematic theoretical treatment of the complicated hadronic dynamics is strongly desired. QCD Factorization represents a model-independent framework to compute hadronic matrix elements from first principles. It is based on a power expansion in {lambda}{sub QCD}/m{sub b} and allows for the systematic implementation of perturbative corrections. In particular, we consider hadronic two-body decays as B {yields} {pi}{pi} and perform a conceptual analysis of heavy-to-light form factors which encode the strong interaction effects in semi-leptonic decays as B {yields} {pi}l{nu}. Concerning the hadronic decays we compute NNLO QCD corrections which are particularly important with respect to strong interaction phases and hence direct CP asymmetries. On the technical level, we perform a 2-loop calculation which is based on an automatized reduction algorithm and apply sophisticated techniques for the calculation of loop-integrals. We indeed find that the considered quantities are well-defined as predicted by QCD Factorization, which is the result of a highly complicated subtraction procedure. We present results for the imaginary part of the topological tree amplitudes and observe that the considered corrections are substantial. The calculation of the real part of the amplitudes is far more complicated and we present a preliminary result which is based on certain simplifications. Our calculation is one part of the full NNLO analysis of nonleptonic B decays within QCD Factorization which is currently pursued by various groups. In our conceptual analysis of the QCD dynamics in heavy-to-light transitions we consider form factors between non
Competition and evolution of dielectric waveguide mode and plasmonic waveguide mode
Yuan, Sheng-Nan; Fang, Yun-Tuan
2017-10-01
In order to study the coupling and evolution law of the waveguide mode and two plasmonic surface modes, we construct a line defect waveguide based on hexagonal honeycomb plasmonic photonic crystal. Through adjusting the radius of the edge dielectric rods, the competition and evolution behaviors occur between dielectric waveguide mode and plasmonic waveguide mode. There are three status: only plasmonic waveguide modes occur for rA 0.25a; two kinds of modes coexist for 0.09a slow light.
Broad-band robustly single-mode hollow-core PCF by resonant filtering of higher order modes
Günendi, Mehmet C; Frosz, Michael H; Russell, Philip St J
2015-01-01
We propose and theoretically analyse a novel hollow-core photonic crystal fibre (PCF) that is engineered so as to strongly suppress higher order modes, i.e., to provide robust LP$_{01}$ single-mode guidance in all the wavelength ranges where the fibre guides with low loss. Encircling the core is a single ring of non-touching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes, causing them to leak at a very high rate into the supporting solid glass sheath. Using a model based on coupled capillary waveguides, as well as full vectorial finite element modelling, we show that this modal filtering effect depends on only one dimensionless geometrical parameter, akin to the well-known $d/{\\Lambda}$ parameter for endlessly single-mode solid-core PCF. The design is scalable up to large core sizes and is predicted to deliver LP$_{01}$ mode losses of some $10$s of dB/km in multiple transmission windows, the broadest of which spans more than an octave. At the same ...
Analysis of Buried Dielectric Objects Using Higher-Order MoM for Volume Integral Equations
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2004-01-01
A higher-order method of moments (MoM) is applied to solve a volume integral equation for dielectric objects in layered media. In comparison to low-order methods, the higher-order MoM, which is based on higher-order hierarchical Legendre vector basis functions and curvilinear hexahedral elements...
Modular specification and verification for higher-order languages with state
DEFF Research Database (Denmark)
Svendsen, Kasper
-order separation logic. The first chapter presents a higher-order separation logic for a higher-order subset of C#. One of the interesting issues that arises when reasoning about higher-order code in an imperative language, is the combination of mutable variables and variable capture. In C#, anonymous methods can...
Quantization of the Interacting Non-Hermitian Higher Order Derivative Field
Margalli, Carlos A.; Vergara, J. David
2013-01-01
The quantization of higher order time derivative theories including interactions is unclear. In this paper in order to solve this problem, we propose to consider a complex version of the higher order derivative theory and map this theory to a real first order theory. To achieve this relationship, the higher order derivative formulation must be complex since there is not a real canonical transformation from this theory to a real first order theory with stable interactions. In this manner, we w...
An Expansion Formula with Higher-Order Derivatives for Fractional Operators of Variable Order
Almeida, Ricardo
2013-01-01
We obtain approximation formulas for fractional integrals and derivatives of Riemann-Liouville and Marchaud types with a variable fractional order. The approximations involve integer-order derivatives only. An estimation for the error is given. The efficiency of the approximation method is illustrated with examples. As applications, we show how the obtained results are useful to solve differential equations, and problems of the calculus of variations that depend on fractional derivatives of Marchaud type. PMID:24319382
Scattering loss of antiresonant reflecting optical waveguides
Baba, Toshihiko; Kokubun, Yasuo
1991-01-01
Scattering loss of two-dimensional ARROW-type waveguides, i.e., antiresonant reflecting optical waveguide (ARROW) and ARROW-B, is analyzed by the first-order perturbation theory. Calculated results are compared with those of conventional three-layer waveguides. Optimum design for the reduction of scattering loss of these ARROW-type waveguides is discussed. It was found that the scattering loss of ARROW-type waveguides is no larger than that of a conventional waveguide having a relative refrac...
On the expressiveness and decidability of higher-order process calculi
Lanese, Ivan; Perez, Jorge A.; Sangiorgi, Davide; Schmitt, Alan
In higher-order process calculi, the values exchanged in communications may contain processes. A core calculus of higher-order concurrency is studied; it has only the operators necessary to express higher-order communications: input prefix, process output, and parallel composition. By exhibiting a
A review of higher order strain gradient theories of plasticity: Origins ...
Indian Academy of Sciences (India)
However, higher order theories need to be thermodynamically consistent. It has recently been shown that only a few of the existing theories pass this test. We review a few that do. Higher order theories require higher order boundary conditions that enable us to model effects of dislocation storage at impermeable boundaries ...
Spatial mode-selective waveguide with hyperbolic cladding
Tang, Y.; Xi, Z.; Xu, M.; Bäumer, S.M.B.; Adam, A.J.L.; Urbach, H.P.
2016-01-01
Hyperbolic metamaterials (HMMs) are anisotropic materials with a permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as a cladding material, a waveguide that only supports higher-order modes can be achieved, while the lower-order modes
Plasmonic waveguides cladded by hyperbolic metamaterials
DEFF Research Database (Denmark)
Ishii, Satoshi; Shalaginov, Mikhail Y.; Babicheva, Viktoriia E.
2014-01-01
Strongly anisotropic media with hyperbolic dispersion can be used for claddings of plasmonic waveguides (PWs). In order to analyze the fundamental properties of such waveguides, we analytically study 1D waveguides arranged from a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure...
Sreehari, V. M.
2017-08-01
The primary aim of the present work is to calculate and compare the response of composite plate using first order and higher order shear deformation theories. The present study initially attempts to develop a finite element formulation for handling the analysis of laminated composite plates. The current study elaborately discusses the formulation that makes an easy programming even for a beginner in this field. Presently, mathematical formulation and Matlab coding using First Order Shear Deformation Theory (FSDT) and Higher Order Shear Deformation Theory (HSDT) had done. Results obtained were compared with the available literature. Parametric study also conducted to clearly understand the variation in results obtained from both FSDT and HSDT.
Higher-Order Beta Matching with Solutions in Long Beta-Eta Normal Form
DEFF Research Database (Denmark)
Støvring, Kristian
2006-01-01
Higher-order matching is a special case of unification of simply-typed lambda-terms: in a matching equation, one of the two sides contains no unification variables. Loader has recently shown that higher-order matching up to beta equivalence is undecidable, but decidability of higher-order matching...... up to beta-eta equivalence is a long-standing open problem.We show that higher-order matching up to beta-eta equivalence is decidable if and only if a restricted form of higher-order matching up to beta equivalence is decidable: the restriction is that solutions must be in long beta-eta normal form....
Directory of Open Access Journals (Sweden)
K. Y. Kim
2009-06-01
Full Text Available The guided modal properties of double-positive and double-negative metamaterial slab waveguides are numerically analyzed and compared when varying the dielectric and magnetic constants. As the cutoff frequencies of both slab waveguides remained unchanged when the absolute value of the refractive index was kept invariant, this enabled an effective comparison of the respective guided modes. Thus, the guided mode dispersion characteristics of the double-positive and double-negative slab waveguides were analyzed and compared, including several higher order modes. As a result, this comparative analysis provides greater physical insights and a better understanding of the guided modal characteristics of double-negative metamaterial slab waveguides.
Slotted Polyimide-Aerogel-Filled-Waveguide Arrays
Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.
2013-01-01
This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.
Ultrafast Laser Fabrication of Bragg Waveguides in GLS Chalcogenide Glass
Directory of Open Access Journals (Sweden)
McMillen Ben
2013-11-01
Full Text Available We present work on the fabrication of Bragg waveguides in gallium-lanthanum-sulfide chalcogenide glass using an ultrafast laser. Waveguides were written with a single pass while modulating the writing beam. The spatial and temporal profile of the writing beam was ontrolled during waveguide fabrication in order to control the shape and size of the waveguide cross-section.
Compact on-Chip Temperature Sensors Based on Dielectric-Loaded Plasmonic Waveguide-Ring Resonators
Directory of Open Access Journals (Sweden)
Sergey I. Bozhevolnyi
2011-02-01
Full Text Available The application of a waveguide-ring resonator based on dielectric-loaded surface plasmon-polariton waveguides as a temperature sensor is demonstrated in this paper and the influence of temperature change to the transmission through the waveguide-ring resonator system is comprehensively analyzed. The results show that the roundtrip phase change in the ring resonator due to the temperature change is the major reason for the transmission variation. The performance of the temperature sensor is also discussed and it is shown that for a waveguide-ring resonator with the resonator radius around 5 mm and waveguide-ring gap of 500 nm which gives a footprint around 140 µm2, the temperature sensitivity at the order of 10−2 K can be achieved with the input power of 100 mW within the measurement sensitivity limit of a practical optical detector.
Chin-Joe-Kong, M.J.S.; Mulder, W.A.; van Veldhuizen, M.
1999-01-01
The higher-order finite-element scheme with mass lumping for triangles and tetrahedra is an efficient method for solving the wave equation. A number of lower-order elements have already been found. Here the search for elements of higher order is continued. Elements are constructed in a systematic
Geometric numerical integration applied to the elastic pendulum at higher order resonance
Tuwankotta, J.M.; Quispel, G.R.W.
2000-01-01
In this paper we study the performance of a symplectic numerical integrator based on the splitting method This method is applied to a subtle problem ie higher order resonance of the elastic pendulum In order to numerically study the phase space of the elastic pendulum at higher order resonance a
Higher Order Thinking Skills among Secondary School Students in Science Learning
Saido, Gulistan Mohammed; Siraj, Saedah; Bin Nordin, Abu Bakar; Al Amedy, Omed Saadallah
2015-01-01
A central goal of science education is to help students to develop their higher order thinking skills to enable them to face the challenges of daily life. Enhancing students' higher order thinking skills is the main goal of the Kurdish Science Curriculum in the Iraqi-Kurdistan region. This study aimed at assessing 7th grade students' higher order…
The Higher Order Structure of Environmental Attitudes: A Cross-Cultural Examination
Directory of Open Access Journals (Sweden)
Taciano L. Milfont
2010-01-01
Full Text Available Past research has suggested that Preservation and Utilization are the two higher order dimensions forming the hierarchical structure of environmental attitudes. This means that these two higher order dimensions could group all kinds of perceptions or beliefs regarding the natural environment people have. A crosscultural study was conducted in Brazil, New Zealand, and South Africa to test this hierarchical structure of environmental attitudes. Results from single- and multi-group confirmatory factor analyses demonstrated that environmental attitudes are a multidimensional construct, and that their first-order factors associate to each other to form a vertical structure. However, the question whether the vertical structure comprise a single higher order factor or two higher order factors still remains unanswered. These results are discussed and directions for future research trying to demonstrate that Preservation and Utilization, taken as distinct second-order environmental attitudes factors, are more empirically meaningful than a single and generalised environmental attitudes higher order factor are presented.
Jeong, Seok-Hwan; Shimura, Daisuke; Simoyama, Takasi; Seki, Miyoshi; Yokoyama, Nobuyuki; Ohtsuka, Minoru; Koshino, Keiji; Horikawa, Tsuyoshi; Tanaka, Yu; Morito, Ken
2014-03-01
We present flatband, low-loss and low-crosstalk characteristics of Si-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by ArF-immersion lithography process on a 300-mm silicon-on-insulator (SOI) wafer. We theoretically specified why phase controllability over Si-nanowire waveguides is prerequisite to attain desired spectral response, discussing spectral degradation by random phase errors during fabrication process. It was experimentally demonstrated that advanced patterning technology based on ArF-immersion lithography process showed extremely low phase errors even for Si-nanowire channel waveguides. As a result, the device exhibited extremely low loss of CROW. We believe these high-precision fabrication technologies based on 300-mm SOI wafer scale ArF-immersion lithography would be promising for several kinds of WDM multiplexers/demultiplexers having much complicated configurations and requiring much finer phase controllability.
Fractal Dimension Analysis of Higher-Order Mode Shapes for Damage Identification of Beam Structures
Bai, Runbo; Cao, Maosen; Su, Zhongqing; Ostachowicz, Wieslaw; Xu, Hao
2012-01-01
Fractal dimension analysis is an emerging method for vibration-based structural damage identification. An unresolved problem in this method is its incapability of identifying damage by higher-order mode shapes. The natural inflexions of higher-order mode shapes may cause false peaks of high-magnitude estimates of fractal dimension, largely masking any signature of damage. In the situation of a scanning laser vibrometer (SLV) providing a chance to reliably acquire higher-order (around tenth-or...
Lagrangian-Hamiltonian unified formalism for autonomous higher order dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Prieto-Martinez, Pedro Daniel; Roman-Roy, Narciso, E-mail: peredaniel@ma4.upc.edu, E-mail: nrr@ma4.upc.edu [Departamento de Matematica Aplicada IV, Edificio C-3, Campus Norte UPC, C/ Jordi Girona 1, 08034 Barcelona (Spain)
2011-09-23
The Lagrangian-Hamiltonian unified formalism of Skinner and Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, as well as for first-order and higher order field theories. However, a complete generalization to higher order mechanical systems is yet to be described. In this work, after reviewing the natural geometrical setting and the Lagrangian and Hamiltonian formalisms for higher order autonomous mechanical systems, we develop a complete generalization of the Lagrangian-Hamiltonian unified formalism for these kinds of systems, and we use it to analyze some physical models from this new point of view. (paper)
Analysis of Scattering by Inhomogeneous Dielectric Objects Using Higher-Order Hierarchical MoM
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2003-01-01
An efficient technique for the analysis of electromagnetic scattering by arbitrary shaped inhomogeneous dielectric objects is presented. The technique is based on a higher-order method of moments (MoM) solution of the volume integral equation. This higher-order MoM solution comprises recently...... that the condition number of the resulting MoM matrix is reduced by several orders of magnitude in comparison to existing higher-order hierarchical basis functions and, consequently, an iterative solver can be applied even for high expansion orders. Numerical results demonstrate excellent agreement...
PRE-SERVICE MATHEMATICS TEACHERS’ CONCEPTION OF HIGHER-ORDER THINKING LEVEL IN BLOOM'S TAXONOMY
Directory of Open Access Journals (Sweden)
Damianus D Samo
2017-09-01
Full Text Available The purpose of this study is to explore pre-service mathematics teachers' conception of higher-order thinking in Bloom's Taxonomy, to explore pre-service mathematics teachers' ability in categorizing six cognitive levels of Bloom's Taxonomy as lower-order thinking and higher-order thinking, and pre-service mathematics teachers' ability in identifying some questionable items as lower-order and higher-order thinking. The higher-order thinking is the type of non-algorithm thinking which include analytical, evaluative and creative thinking that involves metacognition. This research is a descriptive quantitative research. The data were analyzed and visualized by percentages and diagrams. The participants are 50 Third-Year Students of Mathematics Education Department at Universitas Nusa Cendana. The results showed: (1 pre-service mathematics teachers' conception of lower-order and higher-order thinking more emphasis on the different between the easy and difficult problem, calculation problem and verification problem, conceptual and contextual, and elementary and high-level problem; (2 pre-service mathematics teachers categorized six cognitive levels at the lower-order and higher-order thinking level correctly except at the applying level, preservice mathematics teachers placed it at the higher-order thinking level; (3 pre-service mathematics teacher tend to made the wrong identification of the test questions that were included in the lower-order and higher-order thinking. One of the recommendations is pre-service mathematics teachers should be familiarized of higher-order thinking questions start from their first-year of study in University.
Loss engineered slow light waveguides.
O'Faolain, L; Schulz, S A; Beggs, D M; White, T P; Spasenović, M; Kuipers, L; Morichetti, F; Melloni, A; Mazoyer, S; Hugonin, J P; Lalanne, P; Krauss, T F
2010-12-20
Slow light devices such as photonic crystal waveguides (PhCW) and coupled resonator optical waveguides (CROW) have much promise for optical signal processing applications and a number of successful demonstrations underpinning this promise have already been made. Most of these applications are limited by propagation losses, especially for higher group indices. These losses are caused by technological imperfections ("extrinsic loss") that cause scattering of light from the waveguide mode. The relationship between this loss and the group velocity is complex and until now has not been fully understood. Here, we present a comprehensive explanation of the extrinsic loss mechanisms in PhC waveguides and address some misconceptions surrounding loss and slow light that have arisen in recent years. We develop a theoretical model that accurately describes the loss spectra of PhC waveguides. One of the key insights of the model is that the entire hole contributes coherently to the scattering process, in contrast to previous models that added up the scattering from short sections incoherently. As a result, we have already realised waveguides with significantly lower losses than comparable photonic crystal waveguides as well as achieving propagation losses, in units of loss per unit time (dB/ns) that are even lower than those of state-of-the-art coupled resonator optical waveguides based on silicon photonic wires. The model will enable more advanced designs with further loss reduction within existing technological constraints.
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2007-01-01
The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...
Kuschel, S.; Förster, J.; Denzler, M.
2010-01-01
Three experiments examine the hypothesis that subtle cues of approach orientation facilitate access to higher order information, whereas subtle cues of avoidance orientation impede it. To test these predictions, in two studies, a backward-masking paradigm thought to measure access to higher order
On the Continuity Condition for the Higher-Order VSIE-MoM Formulation
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter
2004-01-01
A higher-order method of moments (MoM) solution of the volume-surface integral equation (VSIE) based on the higher-order hierarchical Legendre basis functions is presented. The technique is suitable for solving electromagnetic problems involving composite metallic-dielectric objects. Numerical...
From "Hello" to Higher-Order Thinking: The Effect of Coaching and Feedback on Online Chats
Stein, David S.; Wanstreet, Constance E.; Slagle, Paula; Trinko, Lynn A.; Lutz, Michelle
2013-01-01
This exploratory study examined the effect of a coaching and feedback intervention in teaching presence and social presence on higher-order thinking in an online community of inquiry. Coaching occurred before each chat, and feedback was provided immediately afterwards. The findings suggest that over time, the frequency of higher-order thinking…
Generation of higher order Gauss-Laguerre modes in single-pass 2nd harmonic generation
DEFF Research Database (Denmark)
Buchhave, Preben; Tidemand-Lichtenberg, Peter
2008-01-01
We present a realistic method for dynamic simulation of the development of higher order modes in second harmonic generation. The deformation of the wave fronts due to the nonlinear interaction is expressed by expansion in higher order Gauss-Laguerre modes....
Multi-domain, higher order level set scheme for 3D image segmentation on the GPU
DEFF Research Database (Denmark)
Sharma, Ojaswa; Zhang, Qin; Anton, François
2010-01-01
to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming...
Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach
Wang, Shouhong; Wang, Hai
2011-01-01
One vision of education evolution is to change the modes of thinking of students. Critical thinking, design thinking, and system thinking are higher order thinking paradigms that are specifically pertinent to business education. A model-directed approach to teaching and learning higher order thinking is proposed. An example of application of the…
Tanujaya, Benidiktus; Mumu, Jeinne; Margono, Gaguk
2017-01-01
Higher order thinking skills (HOTS) is one of important aspects in education. Students with high level of higher order thinking skills tend to be more successful. However, do this phenomenon also happen in the learning of Mathematics? To answer this question, this research aims to study the relationship between HOTS and students' academic…
Ability, Breadth, and Parsimony in Computational Models of Higher-Order Cognition
Cassimatis, Nicholas L.; Bello, Paul; Langley, Pat
2008-01-01
Computational models will play an important role in our understanding of human higher-order cognition. How can a model's contribution to this goal be evaluated? This article argues that three important aspects of a model of higher-order cognition to evaluate are (a) its ability to reason, solve problems, converse, and learn as well as people do;…
Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels
Yilmaz, Ferkan
2012-03-01
In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.
Tunneling dynamics of Bose—Einstein condensates with higher-order interactions in optical lattice
Tie, Lu; Xue, Ju-Kui
2011-12-01
The nonlinear Landau—Zener tunneling and nonlinear Rabi oscillations of Bose—Einstein condensate (BEC) with higher-order atomic interaction between the Bloch bands in an accelerating optical lattice are discussed. Within the two-level model, the tunneling probability of BEC with higher-order atomic interaction between Bloch bands is obtained. We finds that the tunneling rate is closely related to the higher-order atomic interaction. Furthermore, the nonlinear Rabi oscillations of BEC with higher-order atomic interaction between the bands are discussed by imposing a periodic modulation on the level bias. Analytical expressions of the critical higher-order atomic interaction for suppressing/enhancing the Rabi oscillations are obtained. It is shown that the critical value strongly depends on the modulation parameters (i.e., the modulation amplitude and frequency) and the strength of periodic potential.
Subsorted Partial Higher-order Logic as an Extension of CASL
DEFF Research Database (Denmark)
Haxthausen, Anne; Mossakowski, Till; Krieg-Bruckner, Bernd
1999-01-01
CASL is a specification language combining first-order logic, partiality and subsorting. However, inmany applications, first-order logic does not suffice. Consider e.g. the specification of functionalprograms, which often gain their conciseness through the use of higher-order functions, or thespe...
Subsorted Partial Higher-order Logic as an extension of CASL
DEFF Research Database (Denmark)
Mossakowski, T.; Haxthausen, Anne Elisabeth; Krieg-Brückner, B.
2000-01-01
CASL is a specification language combining first-order logic, partiality and subsorting. However, inmany applications, first-order logic does not suffice. Consider e.g. the specification of functionalprograms, which often gain their conciseness through the use of higher-order functions, or thespe...
Directory of Open Access Journals (Sweden)
Erkinjon Karimov
2017-10-01
Full Text Available In this work we discuss higher order multi-term partial differential equation (PDE with the Caputo-Fabrizio fractional derivative in time. Using method of separation of variables, we reduce fractional order partial differential equation to the integer order. We represent explicit solution of formulated problem in particular case by Fourier series.
Higher-order Schrödinger and Hartree–Fock equations
Energy Technology Data Exchange (ETDEWEB)
Carles, Rémi, E-mail: Remi.Carles@math.cnrs.fr [IMAG, UMR5149, CNRS and University Montpellier, CC051, 34095 Montpellier (France); Lucha, Wolfgang, E-mail: Wolfgang.Lucha@oeaw.ac.at [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Moulay, Emmanuel, E-mail: emmanuel.moulay@univ-poitiers.fr [XLIM (UMR-CNRS 7252), University Poitiers, 11 Blvd. Marie et Pierre Curie, BP 30179, 86962 Futuroscope Chasseneuil Cedex (France)
2015-12-15
The domain of validity of the higher-order Schrödinger equations is analyzed for harmonic-oscillator and Coulomb potentials as typical examples. Then, the Cauchy theory for higher-order Hartree–Fock equations with bounded and Coulomb potentials is developed. Finally, the existence of associated ground states for the odd-order equations is proved. This renders these quantum equations relevant for physics.
Novel Object Exploration as a Potential Assay for Higher Order Repetitive Behaviors in Mice.
Steinbach, Jessica M; Garza, Elizabeth T; Ryan, Bryce C
2016-08-20
Restricted, repetitive behaviors (RRBs) are a core feature of autism spectrum disorder (ASD) and disrupt the lives of affected individuals. RRBs are commonly split into lower-order and higher-order components, with lower order RRBs consisting of motor stereotypies and higher order RRBs consisting of perseverative and sequencing behaviors. Higher order RRBs are challenging to model in mice. Current assays for RRBs in mice focus primarily on the lower order components, making basic biomedical research into potential treatments or interventions for higher-order RRBs difficult. Here we describe a new assay, novel object exploration. This assay uses a basic open-field arena with four novel objects placed around the perimeter. The test mouse is allowed to freely explore the arena and the order in which the mouse investigates the novel objects is recorded. From these data, patterned sequences of exploration can be identified, as can the most preferred object for each mouse. The representative data shared here and past results using the novel object exploration assay illustrate that inbred mouse strains do demonstrate different behavior in this assay and that strains with elevated lower order RRBs also show elevated patterned behavior. As such, the novel object exploration assay appears to possess good face validity for higher order RRBs in humans and may be a valuable assay for future studies investigating novel therapeutics for ASD.
The Higher-Order Mode Dampers of the 400 MHz Superconducting LHC Cavities
Häbel, E; Gerigk, F; Zhao, Z T
1997-01-01
The accelerating system of the LHC consists of two structures per beam, each composed of four superconducting single-cell cavities. Their higher-order modes have to be damped sufficiently in order to prevent coupled-bunch instabilities and to limit parasitic mode losses. The first two higher-order modes do not propagate into the beam tubes between the cells. However, strong damping can be obtained with a special dipole mode coupler resonant at both modes. Because of the restricted space, a compact design is used. The other higher-order modes propagate and form coupled modes with unequal field distributions. They are damped by broadband couplers positioned on either side of each cavity cell. We present the design of the higher-order mode couplers together with measurements on a real cavity.
Hiraoka, Takahiro; Ishii, Yuko; Okamoto, Fumiki; Oshika, Tetsuro
2009-02-01
To investigate the influence of cosmetically tinted soft contact lenses on ocular higher-order aberrations and visual performance, and to analyze the relationship between these parameters after the lens wear. In 44 eyes of 22 subjects, visual acuity, contrast sensitivity under photopic and mesopic conditions, and ocular higher-order aberrations were evaluated before and after wearing the tinted soft contact lenses (1-day Acuvue Colours; Vistakon, Jacksonville, FL). Contrast sensitivity under a photopic condition was determined at 3, 6, 12, and 18 cycles per degree, and the area under the log contrast sensitivity function (AULCSF) was calculated. Mesopic contrast sensitivity with and without glare was assessed. Ocular higher-order aberrations for a 4-mm pupil were measured, and coma-like, spherical-like, and total higher-order aberrations were determined. The tinted contact lens wearing resulted in significant decreases in log contrast sensitivity at all spatial frequencies (P 0.05), the changes in total higher-order aberrations showed a significant correlation with those in AULCSF (P 0.05). Cosmetically tinted contact lenses increase ocular higher-order aberrations and worsen contrast sensitivity under both photopic and mesopic conditions. Increases in higher-order aberrations are responsible for decreased contrast sensitivity under the photopic condition. Tinted contact lens wearers should be sufficiently informed about the possible reduction in optical quality of the eye and quality of vision.
Oblique beams interference for mode selection in multimode silicon waveguides
Signorini, Stefano; Borghi, Massimo; Mancinelli, Mattia; Bernard, Martino; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo
2017-09-01
Here, we propose to use the interference pattern which arises from the superposition of two coherent free space tilted beams at the input facet of an optical waveguide to excite selectively a given optical mode. By tuning the period of the interference fringes, it is possible to select the excited mode in the waveguide by maximizing the overlap integral with the modal optical field. Our setup is based on a free space interferometer that is theoretically capable of selectively exciting higher order modes in a micron-sized waveguide with an average cross-talk of 37 dB and a mode selectivity higher than 90%. The system is easily reconfigurable and can be straightforwardly integrated on a chip to enhance miniaturization, compactness, and stability.
Higher order predicted terms for an QCD observable, using PMS procedure
Energy Technology Data Exchange (ETDEWEB)
Bakniehl [Institute for Theoretical Physics-II, Hamburg University, Luruper Chaussee 149, 22761 Hamburg (Germany); Mirjalili, A [Institute for Studies in Theoretical Physics and Mathematics (IPM), 19395-5531, Tehran (Iran, Islamic Republic of)], E-mail: Mirjalili@ipm.ir
2008-05-15
In this letter, we first review the principle of minimum sensitivity (PMS) in NLO, NNLO and higher order approximations to find an optimized expression for the desired observable at specific order. It is possible to expand the optimized quantities in terms of the quantities which exist in the standard approach of QCD for the observable. In this case we are able to obtain the predicted higher order terms. The calculations indicate that the predicted term, in the NNLO and higher approximations is not unique.
On the capabilities of higher-order neurons: a radial basis function approach.
Schmitt, Michael
2005-03-01
Higher-order neurons with k monomials in n variables are shown to have Vapnik-Chervonenkis (VC) dimension at least nk + 1. This result supersedes the previously known lower bound obtained via k-term monotone disjunctive normal form (DNF) formulas. Moreover, it implies that the VC dimension of higher-order neurons with k monomials is strictly larger than the VC dimension of k-term monotone DNF. The result is achieved by introducing an exponential approach that employs gaussian radial basis function neural networks for obtaining classifications of points in terms of higher-order neurons.
Modeling 3D PCMI using the Extended Finite Element Method with higher order elements
Energy Technology Data Exchange (ETDEWEB)
Jiang, W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin W. [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2017-03-31
This report documents the recent development to enable XFEM to work with higher order elements. It also demonstrates the application of higher order (quadratic) elements to both 2D and 3D models of PCMI problems, where discrete fractures in the fuel are represented using XFEM. The modeling results demonstrate the ability of the higher order XFEM to accurately capture the effects of a crack on the response in the vicinity of the intersecting surfaces of cracked fuel and cladding, as well as represent smooth responses in the regions away from the crack.
Effective higher-order nonlinear coefficients of composites with weakly nonlinear media
Natenapit, Mayuree; Thongboonrithi, Chaivej
2010-05-01
The field equations, based on the third-order perturbation expansion of electrostatic potential, are derived, and our general formulae for higher-order effective nonlinear coefficients based on the energy definition, are presented and applied to dielectric composites consisting of dilute linear cylindrical inclusions randomly dispersed in a weakly nonlinear host media. The effective nonlinear coefficients are determined up to the ninth order. In addition, the results are also compared to those obtained using the average field method and likely to provide more accurate predictions of effective higher-order nonlinear responses.
DEFF Research Database (Denmark)
Sondergaard, T.; Bozhevolnyi, S. I.; Beermann, J.
2012-01-01
Transmission through thin metal films with a periodic arrangement of tapered slits is considered. Transmission maps covering a wide range of periods, film thicknesses, and taper angles are presented. The maps show resonant transmission when fundamental and higher-order slit resonances are excited....... A study of the effect on transmission of different combinations of available transmission and reflection diffraction orders show optimum total transmission when only the fundamental reflection order and higher transmission diffraction orders are available. The optimum taper angle is shown...
Wave-guided optical waveguides
DEFF Research Database (Denmark)
Palima, Darwin; Bañas, Andrew Rafael; Vizsnyiczai, George
2012-01-01
in the sample at any orientation using optical traps. One of the key aspects to the work is the change in direction of the incident plane wave, and the marked increase in the numerical aperture demonstrated. Hence, the optically steered waveguide can tap from a relatively broader beam and then generate a more...... tightly confined light at its tip. The paper contains both simulation, related to the propagation of light through the waveguide, and experimental demonstrations using our BioPhotonics Workstation. In a broader context, this work shows that optically trapped microfabricated structures can potentially help...
Fractal Dimension Analysis of Higher-Order Mode Shapes for Damage Identification of Beam Structures
Directory of Open Access Journals (Sweden)
Runbo Bai
2012-01-01
Full Text Available Fractal dimension analysis is an emerging method for vibration-based structural damage identification. An unresolved problem in this method is its incapability of identifying damage by higher-order mode shapes. The natural inflexions of higher-order mode shapes may cause false peaks of high-magnitude estimates of fractal dimension, largely masking any signature of damage. In the situation of a scanning laser vibrometer (SLV providing a chance to reliably acquire higher-order (around tenth-order mode shapes, an improved fractal dimension method that is capable of treating higher-order mode shapes for damage detection is of important significance. This study proposes a sophisticated fractal dimension method with the aid of a specially designed affine transformation that is able to obviate natural inflexions of a higher-order mode shape while preserving its substantial damage information. The affine transformed mode shape facilitates the fractal dimension analysis to yield an effective damage feature: fractal dimension trajectory, in which an abruptly risking peak clearly characterizes the location and severity of the damage. This new fractal dimension method is demonstrated on multiple cracks identification in numerically simulated damage scenarios. The effectiveness of the method is experimentally validated by using a SLV to acquire higher-order mode shapes of a cracked cantilever beam.
Directory of Open Access Journals (Sweden)
J. Neugebauer
2011-12-01
Full Text Available The theory of $u_{0}$-positive operators with respect to a cone in a Banach space is applied to the linear differential equations $u^{(4}+\\lambda_{1} p(xu=0$ and $u^{(4}+\\lambda_{2} q(xu=0$, $0\\leq x\\leq 1$, with each satisfying the boundary conditions $u(0=u^{\\prime}(r=u^{\\prime \\prime}(r=u^{\\prime \\prime \\prime}(1=0$, $0
Higher Order Thinking in the Australian Army Suite of Logistic Officer Courses
National Research Council Canada - National Science Library
Bradford, Scott R
2006-01-01
.... The current Suite of Logistic Officer Courses (SOLOC) has been recently criticized for failing to meet this requirement, with the general perception that there is a distinct lack of higher-order thinking competencies within this continuum...
Existence Results for Higher-Order Boundary Value Problems on Time Scales
Sang Yanbin; Liu Jian
2009-01-01
By using the fixed-point index theorem, we consider the existence of positive solutions for the following nonlinear higher-order four-point singular boundary value problem on time scales , ; , ; , ; , , where , , , , , , , and is rd-continuous.
Visualization and processing of higher order descriptors for multi-valued data
Schultz, Thomas
2015-01-01
Modern imaging techniques and computational simulations yield complex multi-valued data that require higher-order mathematical descriptors. This book addresses topics of importance when dealing with such data, including frameworks for image processing, visualization, and statistical analysis of higher-order descriptors. It also provides examples of the successful use of higher-order descriptors in specific applications and a glimpse of the next generation of diffusion MRI. To do so, it combines contributions on new developments, current challenges in this area, and state-of-the-art surveys. Compared to the increasing importance of higher-order descriptors in a range of applications, tools for analysis and processing are still relatively hard to come by. Even though application areas such as medical imaging, fluid dynamics, and structural mechanics are very different in nature they face many shared challenges. This book provides an interdisciplinary perspective on this topic with contributions from key rese...
A classification scheme for nonoscillatory solutions of a higher order neutral difference equation
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available Nonoscillatory solutions of a nonlinear neutral type higher order difference equations are classified by means of their asymptotic behaviors. By means of the Kranoselskii's fixed point theorem, existence criteria are then provided for justification of such classification.
On the combined effect of the chemical reaction and a higher order ...
African Journals Online (AJOL)
On the combined effect of the chemical reaction and a higher order temparature profile on the velocity of a stretched vertical permeable surface in the magnetohydrodynamic (MHD) flow in the presence of heat generation and absorption.
Deformation from symmetry for Schrodinger equations of higher order on unbounded domains
Directory of Open Access Journals (Sweden)
Addolorata Salvatore
2003-06-01
Full Text Available By means of a perturbation method recently introduced by Bolle, we discuss the existence of infinitely many solutions for a class of perturbed symmetric higher order Schrodinger equations with non-homogeneous boundary data on unbounded domains.
Integrability of the higher-order nonlinear Schrödinger equation revisited
Sakovich, S Yu
1999-01-01
Only the known integrable cases of the Kodama-Hasegawa higher-order nonlinear Schroedinger equation pass the Painleve test. Recent results of Ghosh and Nandy add no new integrable cases of this equation.
Generalizing higher-order Bessel-Gauss beams: analytical description and demonstration.
Schimpf, Damian N; Schulte, Jan; Putnam, William P; Kärtner, Franz X
2012-11-19
We report on a novel class of higher-order Bessel-Gauss beams in which the well-known Bessel-Gauss beam is the fundamental mode and the azimuthally symmetric Laguerre-Gaussian beams are special cases. We find these higher-order Bessel-Gauss beams by superimposing decentered Hermite-Gaussian beams. We show analytically and experimentally that these higher-order Bessel-Gauss beams resemble higher-order eigenmodes of optical resonators consisting of aspheric mirrors. This work is relevant for the many applications of Bessel-Gauss beams in particular the more recently proposed high-intensity Bessel-Gauss enhancement cavities for strong-field physics applications.
On a system of higher-order multi-point boundary value problems
Directory of Open Access Journals (Sweden)
Johnny Henderson
2012-07-01
Full Text Available We investigate the existence and nonexistence of positive solutions for a system of nonlinear higher-order ordinary differential equations subject to some multi-point boundary conditions.
The Need to Deliver Higher-Order Skills in the Context of Marketing in SMEs
Copley, Paul
2013-01-01
It is argued that the delivery of learning and the development of skills and competences are central to SME success; and there appears to be a requirement for higher-order education and training that can deliver a
Higher-Order Wavefront Aberrations for Populations of Young Emmetropes and Myopes
Directory of Open Access Journals (Sweden)
Jinhua Bao
2009-01-01
Conclusions: Human eyes have systematical higher order aberrations in population, and factors that cause bilateral symmetry of wavefront aberrations between the right and left eyes made important contribution to the systematical aberrations.
Higher-order multi-resolution topology optimization using the finite cell method
DEFF Research Database (Denmark)
Groen, Jeroen Peter; Langelaar, Matthijs; Sigmund, Ole
2017-01-01
This article presents a detailed study on the potential and limitations of performing higher-order multi-resolution topology optimization with the finite cell method. To circumvent stiffness overestimation in high-contrast topologies, a length-scale is applied on the solution using filter methods....... This reduction is caused by exploiting the decoupling of density and analysis mesh, and by condensing the higher-order modes out of the stiffness matrix....
Sleep inertia, sleep homeostatic, and circadian influences on higher-order cognitive functions
Burke, Tina M.; Scheer, Frank A. J. L.; Ronda, Joseph M.; Czeisler, Charles A.; Wright, Kenneth P.
2015-01-01
Sleep inertia, sleep homeostatic, and circadian processes modulate cognition, including reaction time, memory, mood, and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-daylong study that included two 14-daylong 28h forced desynchrony protocols, to examine separate and interacting influences of sleep inertia, sleep homeostasis, and circadian phase on higher-order cognitive functions of inhibitory control and selectiv...
Questions for Assessing Higher-Order Cognitive Skills: It's Not Just Bloom?s
Lemons, Paula P.; Lemons, J. Derrick
2013-01-01
We present an exploratory study of biologists? ideas about higher-order cognition questions. We documented the conversations of biologists who were writing and reviewing a set of higher-order cognition questions. Using a qualitative approach, we identified the themes of these conversations. Biologists in our study used Bloom's Taxonomy to logically analyze questions. However, biologists were also concerned with question difficulty, the length of time required for students to address questions...
Phase radiation characteristics of an open-ended circular waveguide
DEFF Research Database (Denmark)
Shishkova, Anna; Pivnenko, Sergey; Kim, Oleksiy S.
2007-01-01
General analytical expressions are derived for the far-field amplitude and phase radiation patterns of an open-ended circular waveguide (OE-CWG) regardless of its radius or the operation frequency for the dominant and symmetric higher-order excitation modes. The derivation is based on the rigorous...... solution to the problem of diffraction at an open end of a waveguide proposed by Weinstein. The near-field amplitude and phase patterns of an OE-CWG are then calculated using the spherical wave expansion technique. The measurement of the radiation pattern of an OE-CWG was carried out to verify the validity...
Higher order aberrations in amblyopic children and their role in refractory amblyopia
Directory of Open Access Journals (Sweden)
Arnaldo Dias-Santos
2014-12-01
Full Text Available Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia, the RA group (24 eyes of 13 children with unilateral refractory amblyopia and the C group (28 eyes of 14 children with normal visual development. Higher order aberrations were evaluated using an OPD-Scan III (NIDEK. Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism, higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia.
Questions for Assessing Higher-Order Cognitive Skills: It's Not Just Bloom’s
Lemons, Paula P.; Lemons, J. Derrick
2013-01-01
We present an exploratory study of biologists’ ideas about higher-order cognition questions. We documented the conversations of biologists who were writing and reviewing a set of higher-order cognition questions. Using a qualitative approach, we identified the themes of these conversations. Biologists in our study used Bloom's Taxonomy to logically analyze questions. However, biologists were also concerned with question difficulty, the length of time required for students to address questions, and students’ experience with questions. Finally, some biologists demonstrated an assumption that questions should have one correct answer, not multiple reasonable solutions; this assumption undermined their comfort with some higher-order cognition questions. We generated a framework for further research that provides an interpretation of participants’ ideas about higher-order questions and a model of the relationships among these ideas. Two hypotheses emerge from this framework. First, we propose that biologists look for ways to measure difficulty when writing higher-order questions. Second, we propose that biologists’ assumptions about the role of questions in student learning strongly influence the types of higher-order questions they write. PMID:23463228
Questions for assessing higher-order cognitive skills: it's not just Bloom's.
Lemons, Paula P; Lemons, J Derrick
2013-01-01
We present an exploratory study of biologists' ideas about higher-order cognition questions. We documented the conversations of biologists who were writing and reviewing a set of higher-order cognition questions. Using a qualitative approach, we identified the themes of these conversations. Biologists in our study used Bloom's Taxonomy to logically analyze questions. However, biologists were also concerned with question difficulty, the length of time required for students to address questions, and students' experience with questions. Finally, some biologists demonstrated an assumption that questions should have one correct answer, not multiple reasonable solutions; this assumption undermined their comfort with some higher-order cognition questions. We generated a framework for further research that provides an interpretation of participants' ideas about higher-order questions and a model of the relationships among these ideas. Two hypotheses emerge from this framework. First, we propose that biologists look for ways to measure difficulty when writing higher-order questions. Second, we propose that biologists' assumptions about the role of questions in student learning strongly influence the types of higher-order questions they write.
Single mode fibers for two stage higher-order soliton compression
Li, Qian; Cheng, Zihao
2017-11-01
Practical fiber designs for two stage third-order soliton compression with single mode fibers are presented. Fiber design rules as well as influences of higher-order dispersion and splicing loss are discussed. A compression factor of 85.92 is achieved with only 60.39% pedestal energy.
Subsorted Partial Higher-order Logic as an Extension of CASL
DEFF Research Database (Denmark)
Mossakowski, Till; Haxthausen, Anne; Krieg-Bruckner, Bernd
1998-01-01
CASL is a specification language combining first-order logic, partiality and subsorting. This paper generalizes the CASL logic to higher-order functions and predicates. The logic is presented in a modular step-by-step reduction. Several possible design alternatives are discussed in the light of t...
Experimental generation and application of the superposition of higher-order Bessel beams
CSIR Research Space (South Africa)
Dudley, Angela L
2009-07-01
Full Text Available This presentation provides information on experimental generation and application of the superposition of higher-order Bessel beams. The superposition of zero order Bessel beams can be used to measure the radius of curvature of a reflecting surface...
Smooth Graphs for Visual Exploration of Higher-Order State Transitions
Blaas, J.; Botha, C.P.; Grundy, E.; Jones, M.W.; Laramee, R.S.; Post, F.H.
2009-01-01
In this paper, we present a new visual way of exploring state sequences in large observational time-series. A key advantage of our method is that it can directly visualize higher-order state transitions. A standard first order state transition is a sequence of two states that are linked by a
The advantage of higher-order theory of mind in the game of limited bidding
De Weerd, H.; Verheij, B.; van Eijck, J.; Verbrugge, L. C.
2011-01-01
Higher-order theory of mind is the ability to recursively model mental states of other agents. It is known that adults in general can reason adequately at the second order (covering attributions like "Alice knows that Bob knows that she wrote a novel under pseudonym"), but there are cognitive limits
A review of higher order strain gradient theories of plasticity: Origins ...
Indian Academy of Sciences (India)
Abstract. In this paper we review developments in higher order strain gradient theories. Several variants of these theories have been proposed in order to explain the effects of size on plastic properties that are manifest in several experiments with micron sized metallic structures. It is generally appreciated that the size effect ...
Blind equalization of underwater acoustic channels using implicit higher-order statistics
Blom, K.C.H.; Dol, Henry S.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria
2016-01-01
In order to reduce the length of transmission time slots and energy consumption of underwater modems, this work focuses on equalization without the need for training sequences. This type of equalization is known as blind equalization. A blind equalizer cascade based on higher-order statistics is
On the effects of wave steepness on higher order Stokes waves ...
African Journals Online (AJOL)
The effect of wave steepness on higher order finite amplitude Stokes waves is investigated analytically and numerically. It is shown that the phase speed increases as the wave steepness increases thereby initiating the wave instabilities. As the order increases, the phase speed also increases .However, the impact of wave ...
A stable higher order space time Galerkin marching-on-in-time scheme
Pray, Andrew J.
2013-07-01
We present a method for the stable solution of time-domain integral equations. The method uses a technique developed in [1] to accurately evaluate matrix elements. As opposed to existing stabilization schemes, the method presented uses higher order basis functions in time to improve the accuracy of the solver. The method is validated by showing convergence in temporal basis function order, time step size, and geometric discretization order. © 2013 IEEE.
Directory of Open Access Journals (Sweden)
Z. Kolka
2002-06-01
Full Text Available State models of dynamical systems used as prototypes in theirpractical realization are optimized from the viewpoint of minimumeigenvalue sensitivities with respect to the change of the individualparameters. In the paper the previously published optimization designprocedure for the second-order linear and piecewise-linear (PWLautonomous dynamical systems [2] is extended also for the higher-ordersystems. Results obtained give the possibility to realize thethird-order basic chaotic or the fourth-order hyper-chaoticoscillators.
An efficient higher-order PML in WLP-FDTD method for time reversed wave simulation
Wei, Xiao-Kun; Shao, Wei; Ou, Haiyan; Wang, Bing-Zhong
2016-09-01
Derived from a stretched coordinate formulation, a higher-order complex frequency shifted (CFS) perfectly matched layer (PML) is proposed for the unconditionally stable finite-difference time-domain (FDTD) method based on weighted Laguerre polynomials (WLPs). The higher-order PML is implemented with an auxiliary differential equation (ADE) approach. In order to further improve absorbing performance, the parameter values of stretching functions in the higher-order PML are optimized by the multi-objective genetic algorithm (MOGA). The optimal solutions can be chosen from the Pareto front for trading-off between two independent objectives. It is shown in a numerical test that the higher-order PML is efficient in terms of attenuating propagating waves and reducing late time reflections. Moreover, the higher-order PML can be placed very close to the wall when analyzing the channel characteristics of time reversal (TR) waves in a multipath indoor environment. Numerical examples of TR wave propagation demonstrate the availability of the proposed method.
Simplification of the Flux Function for a Higher-order Gas-kinetic Evolution Model
Zhou, Guangzhao; Liu, Feng
2016-01-01
The higher-order gas-kinetic scheme for solving the Navier-Stokes equations has been studied in recent years. In addition to the use of higher-order reconstruction techniques, many terms are used in the Taylor expansion of the gas distribution functions. Therefore, a large number of coefficients need to be determined in the calculation of the time evolution of the gas distribution function at cell interfaces. As a consequence, the higher-order flux function takes much more computational time than that of a second-order gas-kinetic scheme. This paper aims to simplify the evolution model by two steps. Firstly, the coefficients related to the higher-order spatial and temporal derivatives of a distribution function are redefined to reduce the computational cost. Secondly, based on the physical analysis, some terms can be removed without loss of accuracy. Through the simplifications, the computational efficiency of the higher-order scheme is increased significantly. In addition, a self-adaptive numerical viscosity...
Optical diagnosis of cervical cancer by higher order spectra and boosting
Pratiher, Sawon; Mukhopadhyay, Sabyasachi; Barman, Ritwik; Pratiher, Souvik; Pradhan, Asima; Ghosh, Nirmalya; Panigrahi, Prasanta K.
2017-03-01
In this contribution, we report the application of higher order statistical moments using decision tree and ensemble based learning methodology for the development of diagnostic algorithms for optical diagnosis of cancer. The classification results were compared to those obtained with an independent feature extractors like linear discriminant analysis (LDA). The performance and efficacy of these methodology using higher order statistics as a classifier using boosting has higher specificity and sensitivity while being much faster as compared to other time-frequency domain based methods.
Hyperentangled photon sources in semiconductor waveguides
DEFF Research Database (Denmark)
Kang, Dongpeng; Helt, L. G.; Zhukovsky, Sergei
2014-01-01
We propose and analyze the performance of a technique to generate mode and polarization hyperentangled photons in monolithic semiconductor waveguides using two concurrent type-II spontaneous parametric down-conversion (SPDC) processes. These two SPDC processes are achieved by waveguide engineering...... which allows for simultaneous modal phase matching with the pump beam in a higher-order mode. Paired photons generated in each process are cross polarized and guided by different guiding mechanisms, which produces entanglement in both polarization and spatial mode. Theoretical analysis shows...... that the output quantum state has a high quality of hyperentanglement by spectral filtering with a bandwidth of a few nanometers, while off-chip compensation is not needed. This technique offers a path to realize an electrically pumped hyperentangled photon source....
Experimental characterization of a quantum many-body system via higher-order correlations
Schweigler, Thomas; Kasper, Valentin; Erne, Sebastian; Mazets, Igor; Rauer, Bernhard; Cataldini, Federica; Langen, Tim; Gasenzer, Thomas; Berges, Jürgen; Schmiedmayer, Jörg
2017-05-01
Quantum systems can be characterized by their correlations. Higher-order (larger than second order) correlations, and the ways in which they can be decomposed into correlations of lower order, provide important information about the system, its structure, its interactions and its complexity. The measurement of such correlation functions is therefore an essential tool for reading, verifying and characterizing quantum simulations. Although higher-order correlation functions are frequently used in theoretical calculations, so far mainly correlations up to second order have been studied experimentally. Here we study a pair of tunnel-coupled one-dimensional atomic superfluids and characterize the corresponding quantum many-body problem by measuring correlation functions. We extract phase correlation functions up to tenth order from interference patterns and analyse whether, and under what conditions, these functions factorize into correlations of lower order. This analysis characterizes the essential features of our system, the relevant quasiparticles, their interactions and topologically distinct vacua. From our data we conclude that in thermal equilibrium our system can be seen as a quantum simulator of the sine-Gordon model, relevant for diverse disciplines ranging from particle physics to condensed matter. The measurement and evaluation of higher-order correlation functions can easily be generalized to other systems and to study correlations of any other observable such as density, spin and magnetization. It therefore represents a general method for analysing quantum many-body systems from experimental data.
Higher-Order Interactions in Quantum Optomechanics: Analytical Solution of Nonlinearity
Directory of Open Access Journals (Sweden)
Sina Khorasani
2017-12-01
Full Text Available A method is described to solve the nonlinear Langevin equations arising from quadratic interactions in quantum mechanics. While the zeroth order linearization approximation to the operators is normally used, here, first and second order truncation perturbation schemes are proposed. These schemes employ higher-order system operators, and then approximate number operators with their corresponding mean boson numbers only where needed. Spectral densities of higher-order operators are derived, and an expression for the second-order correlation function at zero time-delay has been found, which reveals that the cavity photon occupation of an ideal laser at threshold reaches 6 − 2 , in good agreement with extensive numerical calculations. As further applications, analysis of the quantum anharmonic oscillator, calculation of Q-functions, analysis of quantum limited amplifiers, and nondemoliton measurements are provided.
Tuning PID controllers for higher-order oscillatory systems with improved performance.
Malwatkar, G M; Sonawane, S H; Waghmare, L M
2009-07-01
In this paper, model based design of PID controllers is proposed for higher-order oscillatory systems. The proposed method has no limitations regarding systems order, time delays and oscillatory behavior. The reduced model is achieved based on third-order modeling and selection of coefficients through the use of frequency responses. The tuning of the PID parameters are obtained from a reduced third-order model; the procedure seems to be simple and effective, and improved performance of the overall system can be achieved. Three simulation examples and one real-time experiment are included to demonstrate the effectiveness and applicability of the proposed method to systems with oscillatory behavior.
Nanophotonic waveguide enhanced Raman spectroscopy of biological submonolayers
Dhakal, Ashim; Peyskens, Frédéric; Jans, Karolien; Thomas, Nicolas Le; Baets, Roel
2016-01-01
Characterizing a monolayer of biological molecules has been a major challenge. We demonstrate nanophotonic wave-guide enhanced Raman spectroscopy (NWERS) of monolayers in the near-infrared region, enabling real-time measurements of the hybridization of DNA strands and the density of sub-monolayers of biotin-streptavidin complex immobilized on top of a photonics chip. NWERS is based on enhanced evanescent excitation and collection of spontaneous Raman scattering near nanophotonic waveguides, which for a one centimeter silicon nitride waveguide delivers a signal that is more than four orders of magnitude higher in comparison to a confocal Raman microscope. The reduced acquisition time and specificity of the signal allows for a quantitative and real-time characterization of surface species, hitherto not possible using Raman spectroscopy. NWERS provides a direct analytic tool for monolayer research and also opens a route to compact microscope-less lab-on-a-chip devices with integrated sources, spectrometers and d...
Changes of higher-order aberrations with the use of various mydriatics.
Kim, Jae-Hyung; Lim, Taehyung; Kim, Myoung Joon; Tchah, Hungwon
2009-11-01
Advances in corneal refractive surgery have allowed ophthalmologists to correct ocular higher-order aberrations. To obtain more information on the ocular aberrations generated from the optical axis, mydriasis is required. The aim of this study is to evaluate the changes in higher-order aberrations with the use of various mydriatics. Higher-order aberrations were measured in 21 eyes of 21 subjects (age range 24-37 years; 13 males, 8 females). Repeated measurements were conducted before and after the installation of three different mydriatics: 10% phenylephrine, 1% tropicamide, or 1% cyclopentolate. At a pupil size of 6 mm, the average root mean square value of higher-order aberrations (HO-RMS) was 0.430 mum in undilated eyes, and 0.413, 0.410, and 0.477 mum after installation of phenylephrine, tropicamide, and cyclopentolate, respectively. There were no statistically significant differences in the HO-RMS between the four conditions. There was a significant difference in the spherical aberration between the undilated or phenylephrine-treated eyes, compared to those treated with tropicamide or cyclopentolate. Cycloplegic mydriatics seemed to shift spherical aberration in a positive direction. These results suggest that mydriatics may affect higher-order aberrations, especially spherical aberration, and this should be considered when performing wavefront analysis and when correcting wavefront errors.
Analysis of warping deformation modes using higher order ANCF beam element
Orzechowski, Grzegorz; Shabana, Ahmed A.
2016-02-01
Most classical beam theories assume that the beam cross section remains a rigid surface under an arbitrary loading condition. However, in the absolute nodal coordinate formulation (ANCF) continuum-based beams, this assumption can be relaxed allowing for capturing deformation modes that couple the cross-section deformation and beam bending, torsion, and/or elongation. The deformation modes captured by ANCF finite elements depend on the interpolating polynomials used. The most widely used spatial ANCF beam element employs linear approximation in the transverse direction, thereby restricting the cross section deformation and leading to locking problems. The objective of this investigation is to examine the behavior of a higher order ANCF beam element that includes quadratic interpolation in the transverse directions. This higher order element allows capturing warping and non-uniform stretching distribution. Furthermore, this higher order element allows for increasing the degree of continuity at the element interface. It is shown in this paper that the higher order ANCF beam element can be used effectively to capture warping and eliminate Poisson locking that characterizes lower order ANCF finite elements. It is also shown that increasing the degree of continuity requires a special attention in order to have acceptable results. Because higher order elements can be more computationally expensive than the lower order elements, the use of reduced integration for evaluating the stress forces and the use of explicit and implicit numerical integrations to solve the nonlinear dynamic equations of motion are investigated in this paper. It is shown that the use of some of these integration methods can be very effective in reducing the CPU time without adversely affecting the solution accuracy.
Reverse-symmetry waveguides: Theory and fabrication
DEFF Research Database (Denmark)
Horvath, R.; Lindvold, Lars René; Larsen, N.B.
2002-01-01
We present an extensive theoretical analysis of reverse-symmetry waveguides with special focus on their potential application as sensor components in aqueous media and demonstrate a novel method for fabrication of such waveguides. The principle of reverse symmetry is based on making the refractiv...... has the advantage of deeper penetration of the evanescent electromagnetic field into the cover medium, theoretically permitting higher sensitivity to analytes compared to traditional waveguide designs. We present calculated sensitivities and probing depths of conventional and reverse...
Learning about the world: developing higher order thinking in music education
Directory of Open Access Journals (Sweden)
Jaco Kruger
2012-07-01
Full Text Available Innovative thinking is an innate human capacity geared towards adaptation and survival. Theories of education accordingly aim at developing teaching-learning strategies that promote creative, problem-solving reasoning referred to as higher order thinking. This essay briefly explains some of the assumptions underlying this concept, and then suggests how they may be reconfigured in a strategy suitable for education in and through music. The strategy involves a basic process of analysis, evaluation and creativity related to actual social experience. Higher order thinking therefore aims to equip learners with the capacity to synthesise relationships in and beyond particular fields of study so that their thinking may expand into the concreteness of the world. Keywords: social challenges, higher order thinking, education, music education, culture contact, Frère Jacques Disciplines: Disciplines: education, music education, musicology, history, anthropology, folklore studies, philosophy of art
Guang, Hui; Wang, Yajun; Zhang, Lianxin; Li, Lulu; Li, Ming; Ji, Linhong
2017-03-10
Accurate wavefront integration based on gradient fields is crucial for various indirect measurement techniques, such as Shack-Hartmann sensing, shearography, and the fringe reflection technique. In this paper, a higher-order iterative compensation algorithm is proposed to enhance the reconstruction accuracy for the finite-difference-based least-squares integration (FLI) method. In this method, higher-order gradient fields are reconstructed and the calculated residual gradient fields compensate the truncation error with the traditional FLI by iterations. A comparison of different FLI methods, including traditional FLI, iterative FLI, higher-order FLI, and the proposed FLI method, is conducted. The result shows that the reconstructed wavefront with the proposed method is more accurate than those with other FLI methods. In addition, the impact of the gradient measurement noise is also discussed.
Collocated electrodynamic FDTD schemes using overlapping Yee grids and higher-order Hodge duals
Deimert, C.; Potter, M. E.; Okoniewski, M.
2016-12-01
The collocated Lebedev grid has previously been proposed as an alternative to the Yee grid for electromagnetic finite-difference time-domain (FDTD) simulations. While it performs better in anisotropic media, it performs poorly in isotropic media because it is equivalent to four overlapping, uncoupled Yee grids. We propose to couple the four Yee grids and fix the Lebedev method using discrete exterior calculus (DEC) with higher-order Hodge duals. We find that higher-order Hodge duals do improve the performance of the Lebedev grid, but they also improve the Yee grid by a similar amount. The effectiveness of coupling overlapping Yee grids with a higher-order Hodge dual is thus questionable. However, the theoretical foundations developed to derive these methods may be of interest in other problems.
FitzPatrick, Beverly; Hawboldt, John; Doyle, Daniel; Genge, Terri
2015-02-17
To determine whether national educational outcomes, course objectives, and classroom assessments for 2 therapeutics courses were aligned for curricular content and cognitive processes, and if they included higher-order thinking. Document analysis and student focus groups were used. Outcomes, objectives, and assessment tasks were matched for specific therapeutics content and cognitive processes. Anderson and Krathwohl's Taxonomy was used to define higher-order thinking. Students discussed whether assessments tested objectives and described their thinking when responding to assessments. There were 7 outcomes, 31 objectives, and 412 assessment tasks. The alignment for content and cognitive processes was not satisfactory. Twelve students participated in the focus groups. Students thought more short-answer questions than multiple choice questions matched the objectives for content and required higher-order thinking. The alignment analysis provided data that could be used to reveal and strengthen the enacted curriculum and improve student learning.
Higher order mode laser beam intensity fluctuations in strong oceanic turbulence
Baykal, Yahya
2017-05-01
Intensity fluctuations of the higher order mode laser beams are evaluated when these beams propagate in a medium exhibiting strong oceanic turbulence. Our formulation involves the modified Rytov solution that extends the Rytov solution to cover strong turbulence as well, and our recently reported expression that relates the atmospheric turbulence structure constant to the oceanic turbulence parameters and oceanic wireless optical communication link parameters. The variations of the intensity fluctuations are reported against the changes of the ratio of temperature to salinity contributions to the refractive index spectrum, rate of dissipation of kinetic energy per unit mass of fluid, rate of dissipation of mean-squared temperature, viscosity and the source size of the higher order mode laser beam. Our results indicate that under any oceanic turbulence parameters, it is advantageous to employ higher order laser modes in reducing the scintillation noise in wireless optical communication links operating in a strongly turbulent ocean.
Equivalence of two Fixed-Point Semantics for Definitional Higher-Order Logic Programs
Directory of Open Access Journals (Sweden)
Angelos Charalambidis
2015-09-01
Full Text Available Two distinct research approaches have been proposed for assigning a purely extensional semantics to higher-order logic programming. The former approach uses classical domain theoretic tools while the latter builds on a fixed-point construction defined on a syntactic instantiation of the source program. The relationships between these two approaches had not been investigated until now. In this paper we demonstrate that for a very broad class of programs, namely the class of definitional programs introduced by W. W. Wadge, the two approaches coincide (with respect to ground atoms that involve symbols of the program. On the other hand, we argue that if existential higher-order variables are allowed to appear in the bodies of program rules, the two approaches are in general different. The results of the paper contribute to a better understanding of the semantics of higher-order logic programming.
Higher-order structure of the 30-nm chromatin fiber revealed by cryo-EM.
Zhu, Ping; Li, Guohong
2016-11-01
Genomic DNA is hierarchically packaged into chromatin in eukaryotes. As a central-level chromatin structure between nucleosomal arrays and higher order organizations, 30 nm chromatin fiber, and its dynamics play a crucial role in regulating DNA accessibility for gene transcription. However, despite extensive efforts over three decades, the higher-order structure of the 30 nm chromatin fiber remains unresolved and controversial. We have recently reconstituted the 30 nm chromatin fibers from 12 nucleosomal arrays in vitro in the presence of linker histone H1, and determined their cryo-EM structures at resolution of 11 Å (Song et al., Science 344, 376-380). Here, we briefly reviewed the higher-order structure studies of chromatin fibers, mainly focusing on the insights from the cryo-EM structures we recently solved. © 2016 IUBMB Life, 68(11):873-878, 2016. © 2016 International Union of Biochemistry and Molecular Biology.
A new fuzzy multi-objective higher order moment portfolio selection model for diversified portfolios
Yue, Wei; Wang, Yuping
2017-01-01
Due to the important effect of the higher order moments to portfolio returns, the aim of this paper is to make use of the third and fourth moments for fuzzy multi-objective portfolio selection model. Firstly, in order to overcome the low diversity of the obtained solution set and lead to corner solutions for the conventional higher moment portfolio selection models, a new entropy function based on Minkowski measure is proposed as a new objective function and a novel fuzzy multi-objective weighted possibilistic higher order moment portfolio model is presented. Secondly, to solve the proposed model efficiently, a new multi-objective evolutionary algorithm is designed. Thirdly, several portfolio performance evaluation techniques are used to evaluate the performance of the portfolio models. Finally, some experiments are conducted by using the data of Shanghai Stock Exchange and the results indicate the efficiency and effectiveness of the proposed model and algorithm.
Saba, Walid S.
2008-01-01
In this paper we suggest a typed compositional seman-tics for nominal compounds of the form [Adj Noun] that models adjectives as higher-order polymorphic functions, and where types are assumed to represent concepts in an ontology that reflects our commonsense view of the world and the way we talk about it in or-dinary language. In addition to [Adj Noun] compounds our proposal seems also to suggest a plausible explana-tion for well known adjective ordering restrictions.
Majumdar, A. K.
1979-01-01
Expressions are derived for higher-order skewness and excess coefficients using central moments and cumulants up to 8th order. These coefficients are then calculated for three probability distributions: (1) Log-normal, (2) Rice-Nakagami, and (3) Gamma distributions. Curves are given to shown the variation of skewness with excess coefficients for these distributions. These curves are independent of the particular distribution parameters. This method is useful for studying fluctuating phenomena, which obey non-Gaussian statistics.
In-service teacher education: asking questions for higher order thinking in visual literacy
Visvaganthie Moodley
2013-01-01
The kinds of questions teachers ask may thwart or promote learner high-order thinking; teachers themselves must have expertise in questioning skills to promote higher order cognition among learners. Drawing on experiential knowledge of assessment, and as an English-teaching professional development programme (PDP) facilitator, I demonstrate that within the framework of a carefully structured subject-specific PDP, teachers can be taught how to enhance thinking skills in the English visual lite...
Assessment choices to target higher order learning outcomes: the power of academic empowerment
Directory of Open Access Journals (Sweden)
Margot McNeill
2012-09-01
Full Text Available Assessment of higher order learning outcomes such as critical thinking, problem solving and creativity has remained a challenge for universities. While newer technologies such as social networking tools have the potential to support these intended outcomes, academics’ assessment practice is slow to change. University mission statements and unit outlines may purport the value of higher order skills; however, questions remain about how well academics are equipped to design their curriculum and particularly their assessment strategies accordingly. This paper reports on an investigation of academic practice in assessing higher order learning in their units. Despite their intentions towards higher order learning outcomes for their students, the results suggest academics may make decisions when planning their assessment tasks that inadvertently lead students on the path towards lower order outcomes. Among the themes to emerge from the study is the importance of academics’ confidence and their attitudes towards the role of assessment in learning and how these perspectives, along with the types of learning outcomes they intend for their students, can influence their task design.
Higher order wave loads on and response of an articulated tower
Energy Technology Data Exchange (ETDEWEB)
Utne, N.; Fause, S.; Toerum, A. [Norwegian Inst. of Tech., Trondheim (Norway)
1995-12-31
A theoretical and experimental study has been carried out on the higher order wave load phenomena frequently called ringing. It has been shown that a significant mechanism for the ringing effect is impulse type wave loading around the still water line area on an articulated tower. In this paper the authors report on an experimental and theoretical study undertaken to explore the mechanism for the ringing. Several avenues were followed to explore the phenomenon of ringing like higher order wave theory effects and special wave loads effects in the surf zone. Both regular and irregular waves were used during the tests.
Developing higher-order thinking skills with concept mapping: A case of pedagogic frailty
Directory of Open Access Journals (Sweden)
Alberto J. Cañas
2017-09-01
Full Text Available Concept maps have been proposed as a tool that can help develop and exercise higher-order thinking skills, including critical thinking, reflective thinking, synthesis, analysis, among others. In this paper, we review how the different aspects of constructing a concept map can help develop and exercise these skills, and discuss why most students never reach the level of concept mapping skills required to exercises their higher-order thinking skills, in what we propose is a case of pedagogic frailty involving the ‘Pedagogy and Discipline’ and ‘Locus of Control’ dimensions.
Higher order moment description of supercontinuum noise and rogue wave statistics
DEFF Research Database (Denmark)
Sørensen, Simon Toft; Bang, Ole; Dudley, John M.
We quantify the noise properties of supercontinuum (SC) generation in optical fibers using higher-order central moments. The higher-order moments quantify not only the mean and variance of a distribution, but also the asymmetry and the presence of long tails, and are thus particularly useful...... for identifying regions of long-tailed rogue wave like behaviour. By carrying out multiple numerical simulations in the presence of noise, we demonstrate that the statistical moments of Coefficient of Variation, Skew and Kurtosis provide the necessary rigorous measure of the SC histograms to yield a clear means...
Nano-optical conveyor belt with waveguide-coupled excitation.
Wang, Guanghui; Ying, Zhoufeng; Ho, Ho-pui; Huang, Ying; Zou, Ningmu; Zhang, Xuping
2016-02-01
We propose a plasmonic nano-optical conveyor belt for peristaltic transport of nano-particles. Instead of illumination from the top, waveguide-coupled excitation is used for trapping particles with a higher degree of precision and flexibility. Graded nano-rods with individual dimensions coded to have resonance at specific wavelengths are incorporated along the waveguide in order to produce spatially addressable hot spots. Consequently, by switching the excitation wavelength sequentially, particles can be transported to adjacent optical traps along the waveguide. The feasibility of this design is analyzed using three-dimensional finite-difference time-domain and Maxwell stress tensor methods. Simulation results show that this system is capable of exciting addressable traps and moving particles in a peristaltic fashion with tens of nanometers resolution. It is the first, to the best of our knowledge, report about a nano-optical conveyor belt with waveguide-coupled excitation, which is very important for scalability and on-chip integration. The proposed approach offers a new design direction for integrated waveguide-based optical manipulation devices and its application in large scale lab-on-a-chip integration.
Computation of Higher-order Symmetries for Nonlinear Evolution and Lattice Equations
Goktas, U; Goktas, Unal; Hereman, Willy
1998-01-01
A straightforward algorithm for the symbolic computation of higher-order symmetries of nonlinear evolution equations and lattice equations is presented. The scaling properties of the evolution or lattice equations are used to determine the polynomial form of the higher-order symmetries. The coefficients of the symmetry can be found by solving a linear system. The method applies to polynomial systems of PDEs of first-order in time and arbitrary order in one space variable. Likewise, lattices must be of first order in time but may involve arbitrary shifts in the discretized space variable. The algorithm is implemented in Mathematica and can be used to test the integrability of both nonlinear evolution equations and semi-discrete lattice equations. With our Integrability Package, higher-order symmetries are obtained for several well-known systems of evolution and lattice equations. For PDEs and lattices with parameters, the code allows one to determine the conditions on these parameters so that a sequence of hig...
Higher-order stochastic differential equations and the positive Wigner function
Drummond, P. D.
2017-12-01
General higher-order stochastic processes that correspond to any diffusion-type tensor of higher than second order are obtained. The relationship of multivariate higher-order stochastic differential equations with tensor decomposition theory and tensor rank is explained. Techniques for generating the requisite complex higher-order noise are proved to exist either using polar coordinates and γ distributions, or from products of Gaussian variates. This method is shown to allow the calculation of the dynamics of the Wigner function, after it is extended to a complex phase space. The results are illustrated physically through dynamical calculations of the positive Wigner distribution for three-mode parametric downconversion, widely used in quantum optics. The approach eliminates paradoxes arising from truncation of the higher derivative terms in Wigner function time evolution. Anomalous results of negative populations and vacuum scattering found in truncated Wigner quantum simulations in quantum optics and Bose-Einstein condensate dynamics are shown not to occur with this type of stochastic theory.
Children’s higher order cognitive abilities and the development of secondary memory
De Alwis, Duneesha; Myerson, Joel; Hershey, Tamara; Hale, Sandra
2009-01-01
The relations between higher cognitive abilities and immediate and delayed recall were studied in 57 children (6–16 years of age). The participants were tested repeatedly on free recall of a supraspan list (Children’s Memory Scale), and their fluid ability was also assessed (Woodcock–Johnson III Spatial Relations). Consistent with Unsworth and Engle’s (2007) account of the relation between memory and higher order cognition, the children’s fluid ability was significantly correlated with retrie...
Design Procedure for Compact Folded Waveguide Filters
DEFF Research Database (Denmark)
Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy
-dimensional full-wave electromagnetic simulations. The proposed structure and the fabricated folded waveguide filter are shown in Fig. 1. A network analyzer (HP8720D) was used to test the fabricated folded waveguide filter. The measurement results are shown in Fig. 2 in comparison with the simulation results......Waveguide filters are widely used in communication systems due to low losses and high power handling capabilities. One drawback of the conventional waveguide filters is their large size, especially for low-frequency and high-order realizations. It has been shown that the footprint of conventional...... waveguide resonators can be reduced to one quarter by folding the electric and magnetic fields inside the cavity (J. S. Hong, Microwave Symposium Digest, 2004, Vol. 1, pp. 213-216). This paper presents a novel systematic procedure for designing compact low-loss bandpass filters by using folded waveguide...
Higher-order schemes for the Laplace transformation method for parabolic problems
Douglas, C.
2011-01-01
In this paper we solve linear parabolic problems using the three stage noble algorithms. First, the time discretization is approximated using the Laplace transformation method, which is both parallel in time (and can be in space, too) and extremely high order convergent. Second, higher-order compact schemes of order four and six are used for the the spatial discretization. Finally, the discretized linear algebraic systems are solved using multigrid to show the actual convergence rate for numerical examples, which are compared to other numerical solution methods. © 2011 Springer-Verlag.
The power of non-determinism in higher-order implicit complexity
DEFF Research Database (Denmark)
Kop, Cynthia Louisa Martina; Simonsen, Jakob Grue
2017-01-01
We investigate the power of non-determinism in purely functional programming languages with higher-order types. Specifically, we consider cons-free programs of varying data orders, equipped with explicit non-deterministic choice. Cons-freeness roughly means that data constructors cannot occur...... in function bodies and all manipulation of storage space thus has to happen indirectly using the call stack. While cons-free programs have previously been used by several authors to characterise complexity classes, the work on non-deterministic programs has almost exclusively considered programs of data order...
An algorithm to use higher order invariants for modelling potential energy surface of nanoclusters
Jindal, Shweta; Bulusu, Satya S.
2018-02-01
In order to fit potential energy surface (PES) of gold nanoclusters, we have integrated bispectrum features with artificial neural network (ANN) learning technique in this work. We have also devised an algorithm for selecting the frequencies that need to be coupled for extracting the phase information between different frequency bands. We have found that higher order invariant like bispectrum is highly efficient in exploring the PES as compared to other invariants. The sensitivity of bispectrum can also be exploited in acting as an order parameter for calculating many thermodynamic properties of nanoclusters.
Higher-order threshold resummation for semi-inclusive e{sup +}e{sup -} annihilation
Energy Technology Data Exchange (ETDEWEB)
Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences
2009-08-15
The complete soft-enhanced and virtual-gluon contributions are derived for the quark coefficient functions in semi-inclusive e{sup +}e{sup -} annihilation to the third order in massless perturbative QCD. These terms enable us to extend the soft-gluon resummation for the fragmentation functions by two orders to the next-to-next-to-next-to-leading logarithmic (N{sup 3}LL) accuracy. The resummation exponent is found to be the same as for the structure functions in inclusive deep-inelastic scattering. This finding, together with known results on the higher-order quark form factor, facilitates the determination of all soft and virtual contributions of the fourth-order difference of the coefficient functions for these two processes. Unlike the previous (N{sup 2}LL) order in the exponentiation, the numerical effect of the N{sup 3}LL contributions turns out to be negligible at LEP energies. (orig.)
Analyzes of students’ higher-order thinking skills of heat and temperature concept
Slamet Budiarti, Indah; Suparmi, A.; Sarwanto; Harjana
2017-11-01
High order thinking skills refer to three highest domains of the revised Bloom Taxonomy. The aims of the research were to analyze the student’s higher-order thinking skills of heat and temperature concept. The samples were taken by purposive random sampling technique consisted of 85 high school students from 3 senior high schools in Jayapura city. The descriptive qualitative method was employed in this study. The data were collected by using tests and interviews regarding the subject matters of heat and temperature. Based on the results of data analysis, it was concluded that 68.24% of the students have a high order thinking skills in the analysis, 3.53% of the students have a high order thinking skills in evaluating, and 0% of the students have a high order thinking skills in creation.
HIGHER ORDER FACTOR STRUCTURE OF THE WISC-IV IN A CLINICAL NEUROPSYCHOLOGICAL SAMPLE
Bodin, Doug; Pardini, Dustin A.; Burns, Thomas G.; Stevens, Abigail B.
2010-01-01
A confirmatory factor analysis was conducted examining the higher order factor structure of the WISC-IV scores for 344 children who participated in neuropsychological evaluations at a large children’s hospital. The WISC-IV factor structure mirrored that of the standardization sample. The second order general intelligence factor (g) accounted for the largest proportion of variance in the first-order latent factors and in the individual subtests, especially for the working memory index. The first-order processing speed factor exhibited the most unique variance beyond the influence of g. The results suggest that clinicians should not ignore the contribution of g when interpreting the first-order factors. PMID:19132580
Dependence of wave front refraction on pupil size due to the presence of higher order aberrations.
Iseli, H P; Bueeler, M; Hafezi, F; Seiler, T; Mrochen, M
2005-01-01
Propagation of light through the optical pathway within the eye can lead to a deformation of the wave front that might affect objective but also subjective refraction depending on pupil size. The aim of this study was to investigate the change in wave front refraction that is calculated on the basis of second order Zernike polynomials when varying the pupil size from 6 mm to 3 mm. The change was correlated with the amount of fourth and sixth order spherical aberration and fourth and sixth order astigmatism. Wave front aberrations were measured in 130 eyes by means of a Tscherning wave front sensor at a pupil size of 6 mm. Wave front aberrations in terms of Zernike coefficients up to sixth order were approximated for 6 mm and 3 mm pupil size. The wave front refraction was calculated based on the second order Zernike coefficients for both pupil diameters. Resulting differences in wave front refraction (sphere or cylinder) due to the change in pupil size were correlated with the initial higher order aberrations determined for the 6.0 mm pupil by means of a linear regression (Spearman rank correlation coefficient). The correlation between the change in sphere and cylinder on one hand and the spherical aberration and higher order astigmatism on the other hand was found to be highly significant (ppupil size should be established in the ophthalmic community.
Multiple Critical Couplings and Sensing in a Microresonator-Waveguide System
Acharyya, Nirmalendu; Kozyreff, Gregory
2017-09-01
We study the optical transmission of a waveguide that is side coupled to a high-Q circular microresonator. The coupling is critical if the intrinsic resonator losses equal the coupling losses to the waveguide. When this happens, the transmittance of the waveguide displays resonance dips with maximal depth as the frequency is swept through the resonators' resonances. We show that multiple configurations, parametrized by the minimal distance between the resonator and the waveguide, can lead to critical coupling. Indeed, for a sufficiently large resonator radius, the flow of power between the waveguide and the resonator can change sign several times within a single pass. This leads to an oscillatory coupling parameter as a function of the separation distance. As a result, multiple geometrical configurations can lead to critical coupling, even if the waveguide lies in the equatorial plane of the resonator. These results are explained using coupled-mode theory and full-wave numerical simulations. In the vicinity of secondary or higher-order critical coupling, the depth of the transmittance dip is very sensitive to the environment. We discuss how this effect can be exploited for sensing purpose. Alternatively, by actively controlling the environment in the secondary critical configuration, the waveguide-resonator system can be driven as an optical switch.
Directory of Open Access Journals (Sweden)
Littel Marianne
2012-01-01
Full Text Available Abstract Background Classical conditioning has been suggested to play an important role in the development, maintenance, and relapse of tobacco smoking. Several studies have shown that initially neutral stimuli that are directly paired with smoking are able to elicit conditioned responses. However, there have been few human studies that demonstrate the contribution of higher-order conditioning to smoking addiction, although it is assumed that higher-order conditioning predominates learning in the outside world. In the present study a higher-order conditioning task was designed in which brain responses of smokers and non-smokers were conditioned by pairing smoking-related and neutral stimuli (CS1smoke and CS1neutral with two geometrical figures (CS2smoke and CS2neutral. ERPs were recorded to all CSs. Results Data showed that the geometrical figure that was paired with smoking stimuli elicited significantly larger P2 and P3 waves than the geometrical figure that was paired with neutral stimuli. During the first half of the experiment this effect was only present in smokers whereas non-smokers displayed no significant differences between both stimuli, indicating that neutral cues paired with motivationally relevant smoking-related stimuli gain more motivational significance even though they were never paired directly with smoking. These conclusions are underscored by self-reported evidence of enhanced second-order conditioning in smokers. Conclusions It can be concluded that smokers show associative learning for higher-order smoking-related stimuli. The present study directly shows the contribution of higher-order conditioning to smoking addiction and is the first to reveal its electrophysiological correlates. Although results are preliminary, they may help in understanding the etiology of smoking addiction and its persistence.
Littel, Marianne; Franken, Ingmar Ha
2012-01-11
Classical conditioning has been suggested to play an important role in the development, maintenance, and relapse of tobacco smoking. Several studies have shown that initially neutral stimuli that are directly paired with smoking are able to elicit conditioned responses. However, there have been few human studies that demonstrate the contribution of higher-order conditioning to smoking addiction, although it is assumed that higher-order conditioning predominates learning in the outside world. In the present study a higher-order conditioning task was designed in which brain responses of smokers and non-smokers were conditioned by pairing smoking-related and neutral stimuli (CS1smoke and CS1neutral) with two geometrical figures (CS2smoke and CS2neutral). ERPs were recorded to all CSs. Data showed that the geometrical figure that was paired with smoking stimuli elicited significantly larger P2 and P3 waves than the geometrical figure that was paired with neutral stimuli. During the first half of the experiment this effect was only present in smokers whereas non-smokers displayed no significant differences between both stimuli, indicating that neutral cues paired with motivationally relevant smoking-related stimuli gain more motivational significance even though they were never paired directly with smoking. These conclusions are underscored by self-reported evidence of enhanced second-order conditioning in smokers. It can be concluded that smokers show associative learning for higher-order smoking-related stimuli. The present study directly shows the contribution of higher-order conditioning to smoking addiction and is the first to reveal its electrophysiological correlates. Although results are preliminary, they may help in understanding the etiology of smoking addiction and its persistence.
A single dose of oxytocin nasal spray improves higher-order social cognition in schizophrenia.
Guastella, Adam J; Ward, Philip B; Hickie, Ian B; Shahrestani, Sara; Hodge, Marie Antoinette Redoblado; Scott, Elizabeth M; Langdon, Robyn
2015-11-01
Schizophrenia is associated with significant impairments in both higher and lower order social cognitive performance and these impairments contribute to poor social functioning. People with schizophrenia report poor social functioning to be one of their greatest unmet treatment needs. Recent studies have suggested the potential of oxytocin as such a treatment, but mixed results render it uncertain what aspects of social cognition are improved by oxytocin and, subsequently, how oxytocin might best be applied as a therapeutic. The aim of this study was to determine whether a single dose of oxytocin improved higher-order and lower-order social cognition performance for patients with schizophrenia across a well-established battery of social cognition tests. Twenty-one male patients received both a single dose of oxytocin nasal spray (24IU) and a placebo, two weeks apart in a randomized within-subjects placebo controlled design. Following each administration, participants completed the social cognition tasks, as well as a test of general neurocognition. Results revealed that oxytocin particularly enhanced performance on higher order social cognition tasks, with no effects on general neurocognition. Results for individual tasks showed most improvement on tests measuring appreciation of indirect hints and recognition of social faux pas. These results suggest that oxytocin, if combined to enhance social cognition learning, may be beneficial when targeted at higher order social cognition domains. This study also suggests that these higher order tasks, which assess social cognitive processing in a social communication context, may provide useful markers of response to oxytocin in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.
Attenuation in Superconducting Circular Waveguides
Directory of Open Access Journals (Sweden)
K. H. Yeap
2016-09-01
Full Text Available We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.
Oscillation of certain higher-order neutral partial functional differential equations.
Li, Wei Nian; Sheng, Weihong
2016-01-01
In this paper, we study the oscillation of certain higher-order neutral partial functional differential equations with the Robin boundary conditions. Some oscillation criteria are established. Two examples are given to illustrate the main results in the end of this paper.
Temperature variation of higher-order elastic constants of MgO
Indian Academy of Sciences (India)
An effort has been made for obtaining higher-order elastic constants for MgO starting from basic parameters, viz. nearest-neighbor distance and hardness parameter using Coulomb and Börn–Mayer potentials. These are calculated in a wide temperature range (100–1000 K) and compared with available theoretical and ...
Directory of Open Access Journals (Sweden)
Juan Carlos Ceballos V.
2005-10-01
Full Text Available The exact boundary controllability of the higher order nonlinear Schrodinger equation with constant coefficients on a bounded domain with various boundary conditions is studied. We derive the exact boundary controllability for this equation for sufficiently small initial and final states.
Higher-Order Statistical Correlations and Mutual Information Among Particles in a Quantum Well
Yépez, V. S.; Sagar, R. P.; Laguna, H. G.
2017-12-01
The influence of wave function symmetry on statistical correlation is studied for the case of three non-interacting spin-free quantum particles in a unidimensional box, in position and in momentum space. Higher-order statistical correlations occurring among the three particles in this quantum system is quantified via higher-order mutual information and compared to the correlation between pairs of variables in this model, and to the correlation in the two-particle system. The results for the higher-order mutual information show that there are states where the symmetric wave functions are more correlated than the antisymmetric ones with same quantum numbers. This holds in position as well as in momentum space. This behavior is opposite to that observed for the correlation between pairs of variables in this model, and the two-particle system, where the antisymmetric wave functions are in general more correlated. These results are also consistent with those observed in a system of three uncoupled oscillators. The use of higher-order mutual information as a correlation measure, is monitored and examined by considering a superposition of states or systems with two Slater determinants.
Some Opial Dynamic Inequalities Involving Higher Order Derivatives on Time Scales
Directory of Open Access Journals (Sweden)
Samir H. Saker
2012-01-01
Full Text Available We will prove some new Opial dynamic inequalities involving higher order derivatives on time scales. The results will be proved by making use of Hölder's inequality, a simple consequence of Keller's chain rule and Taylor monomials on time scales. Some continuous and discrete inequalities will be derived from our results as special cases.
The grounding of higher order concepts in action and language: a cognitive robotics model.
Stramandinoli, Francesca; Marocco, Davide; Cangelosi, Angelo
2012-08-01
In this paper we present a neuro-robotic model that uses artificial neural networks for investigating the relations between the development of symbol manipulation capabilities and of sensorimotor knowledge in the humanoid robot iCub. We describe a cognitive robotics model in which the linguistic input provided by the experimenter guides the autonomous organization of the robot's knowledge. In this model, sequences of linguistic inputs lead to the development of higher-order concepts grounded on basic concepts and actions. In particular, we show that higher-order symbolic representations can be indirectly grounded in action primitives directly grounded in sensorimotor experiences. The use of recurrent neural network also permits the learning of higher-order concepts based on temporal sequences of action primitives. Hence, the meaning of a higher-order concept is obtained through the combination of basic sensorimotor knowledge. We argue that such a hierarchical organization of concepts can be a possible account for the acquisition of abstract words in cognitive robots. Copyright © 2012 Elsevier Ltd. All rights reserved.
Superpositions of higher-order bessel beams and nondiffracting speckle fields - (SAIP 2009)
CSIR Research Space (South Africa)
Dudley, Angela L
2009-07-01
Full Text Available speckle fields. The paper reports on illuminating a ring slit aperture with light which has an azimuthal phase dependence, such that the field produced is a superposition of two higher-order Bessel beams. In the case that the phase dependence of the light...
A generalized Lyapunov inequality for a higher-order fractional boundary value problem
Directory of Open Access Journals (Sweden)
Dexiang Ma
2016-10-01
Full Text Available Abstract In the paper, we establish a Lyapunov inequality and two Lyapunov-type inequalities for a higher-order fractional boundary value problem with a controllable nonlinear term. Two applications are discussed. One concerns an eigenvalue problem, the other a Mittag-Leffler function.
Higher-order multi-resolution topology optimization using the finite cell method
Groen, J.P.; Langelaar, M.; Sigmund, O; Ruess, M.
2017-01-01
This article presents a detailed study on the potential and limitations of performing higher-order multi-resolution topology optimization with the finite cell method. To circumvent stiffness overestimation in high-contrast topologies, a length-scale is applied on the solution using filter
Higher order point and continuum mechanics from phase-space action
Energy Technology Data Exchange (ETDEWEB)
Shamanna, J.; Talukdar, B.; Das, U
2002-12-02
It is pointed out that use of phase-space action provides an elegant method to study the canonical structure of problems in mechanics. Higher order Lagrangian systems are Hamiltonized by employing the variational principle in phase space. Studies are envisaged for both particle dynamics and field theory. Hamilton's equations are expressed in terms of appropriate Poisson brackets.
Higher-order Bessel like beams with z-dependent cone angles
CSIR Research Space (South Africa)
Ismail, Y
2010-08-01
Full Text Available be produced however at the expense of its non-diffracting nature. Here we outline an optical design to produce higher-order Bessel-like beams with z-dependent cone angles that will retains its spatial distribution as z 8....
Second- and Higher-Order Virial Coefficients Derived from Equations of State for Real Gases
Parkinson, William A.
2009-01-01
Derivation of the second- and higher-order virial coefficients for models of the gaseous state is demonstrated by employing a direct differential method and subsequent term-by-term comparison to power series expansions. This communication demonstrates the application of this technique to van der Waals representations of virial coefficients.…
Reexamining the Literature: The Impact of Peer Tutoring on Higher Order Learning
Morano, Stephanie; Riccomini, Paul J.
2017-01-01
The body of peer-tutoring intervention research targeting higher order learning (HOL) objectives for middle and high school students with disabilities is reviewed. Peer-tutoring outcomes are synthesized and studies are analyzed to examine the influence of tutoring procedures and study design features on intervention efficacy. Findings show that…
Teaching Higher Order Thinking Skills: Implications for Vocational-Technical Education.
Mauter, Margaret A.
The expanding needs and growing expectations of employers make it very clear that vocational-technical education must give concentrated attention to critical thinking, problem solving, and decision making. The impetus for today's higher-order thinking skills movement can be traced to a number of sources, most of which gained prominence during the…
The control operator for the optimal control model of higher order ...
African Journals Online (AJOL)
The control operator of the Extended Conjugate Gradient Algorithm for the control of two- dimensional higher order non-dispersive waves was constructed in the paper. Explicit expressions of each elements, Ri,j , of the operator, R, were computed. These elements are useful for the implementation of the Optimal Control ...
Performance-Based Task Assessment of Higher-Order Proficiencies in Redesigned STEM High Schools
Ernst, Jeremy V.; Glennie, Elizabeth; Li, Songze
2017-01-01
This study explored student abilities in applying conceptual knowledge when presented with structured performance tasks. Specifically, the study gauged proficiency in higher-order applications of students enrolled in earth and environmental science or biology. The student sample was drawn from a Redesigned STEM high school model where a tested…
Compound waves in a higher order nonlinear model of thermoviscous fluids
DEFF Research Database (Denmark)
Rønne Rasmussen, Anders; Sørensen, Mads Peter; Gaididei, Yuri B.
2016-01-01
A generalized traveling wave ansatz is used to investigate compound shock waves in a higher order nonlinear model of a thermoviscous fluid. The fluid velocity potential is written as a traveling wave plus a linear function of space and time. The latter offers the possibility of predicting...
Using Higher Order Thinking Questions to Foster Critical Thinking: A Classroom Study
Barnett, Jerrold E.; Francis, Alisha L.
2012-01-01
To determine if quizzes containing higher order thinking questions are related to critical thinking and test performance when utilised in conjunction with an immersion approach to instruction and effort-based grading, sections of an "Educational Psychology" course were assigned to one of three quizzing conditions. Quizzes contained…
Higher?order ionospheric effects on the GPS reference frame and velocities
Petrie, E.J.; King, M.A.; Moore, P.; Lavallée, D.A.
2010-01-01
We describe how GPS time series are influenced by higher?order ionospheric effects over the last solar cycle (1995–2008) and examine implications for geophysical studies. Using 14 years of globally reprocessed solutions, we demonstrate the effect on the reference frame. Including second? and
Recurrent activity in higher order, modality non-specific brain regions
DEFF Research Database (Denmark)
Lou, Hans Olav Christensen; Joensson, Morten; Biermann-Ruben, Katja
2011-01-01
in the visual system as a response to visual stimulation. In contrast recurrent activity has never been demonstrated before in higher order modality non-specific regions. Using magneto-encephalography and Granger causality analysis, we tested in a paralimbic network the hypothesis that stimulation may enhance...
Directory of Open Access Journals (Sweden)
Yuji Liu
2004-01-01
Full Text Available A new fixed point theorem on cones is applied to obtain the existence of at least two positive solutions of a higher-order three-point boundary value problem for the differential equation subject to a class ofboundary value conditions. The associated Green's function is given. Some results obtained recently are generalized.
Stabilization of solutions to higher-order nonlinear Schrodinger equation with localized damping
Directory of Open Access Journals (Sweden)
Eleni Bisognin
2007-01-01
Full Text Available We study the stabilization of solutions to higher-order nonlinear Schrodinger equations in a bounded interval under the effect of a localized damping mechanism. We use multiplier techniques to obtain exponential decay in time of the solutions of the linear and nonlinear equations.
Superpositions of higher-order bessel beams and nondiffracting speckle fields
CSIR Research Space (South Africa)
Dudley, Angela L
2009-08-01
Full Text Available speckle fields. The paper reports on illuminating a ring slit aperture with light which has an azimuthal phase dependence, such that the field produced is a superposition of two higher-order Bessel beams. In the case that the phase dependence of the light...
Using Tests To Evaluate the Impact of Curricular Reform on Higher Order Thinking.
Davis, Alan
The dominant issues in considering the use of tests developed outside the classroom to measure the impact of curriculum reform on higher order thinking are reviewed by a panel interviewed for this discussion. Panel members are: (1) Stuart Kahl, (2) Robert Linn, (3) Senta A. Raizen, (4) Lauren Resnick, and (5) Thomas A. Romberg. It is conceded…
Topology optimized design of a transverse electric higher order mode converter
DEFF Research Database (Denmark)
Frellsen, Louise Floor; Ding, Yunhong; Sigmund, Ole
2016-01-01
present the possibility of employing topology optimization (TO) to design a device that allows for reversible conversion between the transverse electric fundamental even (TE0) mode and the second higher order odd mode (TE2). Topology optimization is an iterative inverse design process, where repeated...
Higher-order corrected Higgs bosons in FeynHiggs2.4
Indian Academy of Sciences (India)
Abstract. Large higher-order corrections enter the Higgs boson sector of the MSSM via Higgs-boson self-energies. Their effects have to be taken into account for the correct treatment of loop-corrected Higgs-boson mass eigenstates as external (on-shell) or internal particles in Feynman diagrams. We review how the loop ...
Dichotomous Identification Keys: A Ladder to Higher Order Knowledge about the Human Body
Sorgo, Andrej
2006-01-01
We tried to enrich teaching human anatomy in high school biology lessons. Students construct dichotomous identification keys to the cells, tissues, organs, or body parts. By doing this, students have achieved higher-order cognitive levels of knowledge because construction of such keys is based on analysis, synthesis, and evaluation. Students found…
Brady, Timothy F.; Tenenbaum, Joshua B.
2013-01-01
When remembering a real-world scene, people encode both detailed information about specific objects and higher order information like the overall gist of the scene. However, formal models of change detection, like those used to estimate visual working memory capacity, assume observers encode only a simple memory representation that includes no…
A Hybrid PO - Higher-Order Hierarchical MoM Formulation using Curvilinear Geometry Modeling
DEFF Research Database (Denmark)
Jørgensen, E.; Meincke, Peter; Breinbjerg, Olav
2003-01-01
A very efficient hybrid PO-MoM method has been presented. In contrast to existing methods, the present solution employs higher-order hierarchical basis functions to discretize the MoM and PO currents. This allows to reduce the number of basis functions in both the PO and MoM regions considerably...
Numerical computation of the optimal control model of higher-order ...
African Journals Online (AJOL)
The paper implemented the optimal control problem of higher-order nondispersive wave. The Extended Conjugate Gradient Method [1], was used to compute the optimal values of the control and state variables of the model while the analytical expressions of the state and control variables generated the analytical values.
FOOTSTEPS: A Story of One Child's Construction of Higher Order, Logical Mathematical Intelligence.
Fluellen, J. E.
The issue of how a child constructs higher order, logical mathematical intelligence within the context of a multiple-intelligences classroom is explored in this story. Teacher journal observations of one 5th-grade child are woven with selected literature on multiple intelligences and research trends in elementary mathematics education. The story…
Straalen, IJ.J. van
2000-01-01
During tthe 1990's the higher-order theory was developed by Frostig to enable detailed stress analyses of sandwich panel structures. To investigate the potentials of this approach experiments are performed on sandwich panels made of thin steel faces and mineral wool or polystyrene core material. A
Higher-Order Thinking Development through Adaptive Problem-Based Learning
Raiyn, Jamal; Tilchin, Oleg
2015-01-01
In this paper we propose an approach to organizing Adaptive Problem-Based Learning (PBL) leading to the development of Higher-Order Thinking (HOT) skills and collaborative skills in students. Adaptability of PBL is expressed by changes in fixed instructor assessments caused by the dynamics of developing HOT skills needed for problem solving,…
Verifying object-oriented programs with higher-order separation logic in Coq
DEFF Research Database (Denmark)
Bengtson, Jesper; Jensen, Jonas Braband; Sieczkowski, Filip
2011-01-01
and interface inheritance. In particular, we show how to use the higher-order features of the Coq formalisation to specify and reason modularly about programs that (1) depend on some unknown code satisfying a specification or that (2) return objects conforming to a certain specification. All of our results have...
Formalizing Higher-order Mobile Embedded Business Processes with Binding Bigraphs
DEFF Research Database (Denmark)
Bundgaard, Mikkel; Glenstrup, Arne John; Hildebrandt, Thomas
2008-01-01
We propose and formalize HomeBPEL, a higher-order WSBPEL-like business process execution language where processes are firstclass values that can be stored in variables, passed as messages, and activated as embedded sub-instances. A sub-instance is similar to a WSBPEL scope, except that it can...
Describing supercontinuum noise and rogue wave statistics using higher-order moments
DEFF Research Database (Denmark)
Sørensen, Simon Toft; Bang, Ole; Wetzel, Benjamin
2012-01-01
We show that the noise properties of fiber supercontinuum generation and the appearance of long-tailed “rogue wave” statistics can be accurately quantified using statistical higher-order central moments. Statistical measures of skew and kurtosis, as well as the coefficient of variation provide im...
Mierdel, Peter; Krinke, Hans-Eberhard; Pollack, Katharina; Spoerl, Eberhard
2004-01-01
Optimal wavefront-guided refractive corneal laser surgery requires sufficiently exact data of optical higher order aberrations. We investigated whether these aberrations had a systematic during-the-day variation, studied the range of variation, and changes in intraocular pressure and central corneal thickness. In 22 eyes of 22 young volunteers the optical aberrations of higher order were measured by means of a Tscherning-type ocular aberrometer three times during one day (7 AM, 12 noon, 4 PM). In addition, in 12 of these eyes the intraocular pressure and central corneal thickness were measured. The intraocular wavefront aberration was computed using Zernike polynomials up to the sixth order, and Zernike coefficients of third and fourth order were analyzed. Only the coefficient Z 2/4 (C13) showed a significant increase during the day by a mean 0.016 microm. A significant regression could be detected between changes of coefficients Z3/3, Z-2/4, Z0/4, Z4/4, and changes of intraocular pressure or central corneal thickness during the day. Due to the small values, the measured during-the-day changes of higher order aberrations had no direct practical consequences for the aberrometry-guided corneal laser surgery. Alterations of some Zernike coefficients during the day may be explained by the biomechanical behavior of the cornea.
Finite time control for MIMO nonlinear system based on higher-order sliding mode.
Liu, Xiangjie; Han, Yaozhen
2014-11-01
Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
Role of the basolateral amygdala and NMDA receptors in higher-order conditioned fear.
Parkes, Shauna L; Westbrook, R Frederick
2011-01-01
Laboratory rats learn to fear relatively innocuous stimuli which signal the imminent arrival of an innate source of danger, typically brief but aversive foot shock. Much is now known about the neural substrates underlying the acquisition, consolidation and subsequent expression of this fear. Rats also learn to fear stimuli which signal learned sources of danger but relatively little is known about the neural substrates underlying this form of fear. Two Pavlovian conditioning paradigms used to study this form of fear are second-order conditioning and sensory preconditioning. In second-order conditioning, rats are first exposed to a signaling relationship between one stimulus, such as a tone, and aversive foot shock, and then to a signaling relationship between a second stimulus, such as a light, and the now dangerous tone. In sensory preconditioning, these phases are reversed: rats are first exposed to a signaling relationship between the light and the tone and then to a signaling relationship between the tone and the foot shock. In both paradigms, rats exhibit fear when tested with the light. In this review paper, we describe the evidence for higher-order forms of conditioning, the conditions which promote this learning and its contents. We compare and contrast the substrates of the learning underlying second-order and sensory preconditioning fear with those known to underlie the better studied first-order conditioned fear. We conclude with some comments as to the role of higher-order processes in anxiety disorders.
On higher-order boundary conditions at elastic-plastic boundaries in strain-gradient plasticity
DEFF Research Database (Denmark)
Niordson, Christian Frithiof
2008-01-01
are suppressed by using a very high artificial hardening modulus. Through numerical studies of pure bending under plane strain conditions, it is shown that this method predicts the build-up of higher order stresses in the pseudo-elastic regime. This has the effect of delaying the onset of incipient yield......A computational method for dealing with higher order boundary conditions on moving elastic-plastic boundaries in strain gradient plasticity is proposed. The basic idea is to skip the notion of a purely elastic regime, and instead introduce a pseudo-elastic regime, where plastic deformations......, as well as extending the plastic zone further toward the neutral axis of the beam, when compared to conventional models. Arguments supporting the present method are presented that rest on both mathematical and physical grounds. The results obtained are compared with other methods for dealing with higher...
Computation of Higher-Order Moments of Generalized Polynomial Chaos Expansions
Faverjon, Béatrice
2016-01-01
Because of the high complexity of steady-state or transient fluid flow solvers, non-intrusive uncertainty quantification techniques have been developed in aerodynamic simulations in order to compute the output quantities of interest that are required to evaluate the objective function of an optimization process, for example. The latter is commonly expressed in terms of moments of the quantities of interest, such as the mean, standard deviation, or even higher-order moments (skewness, kurtosis...). Polynomial surrogate models based on homogeneous chaos expansions have often been implemented in this respect. The original approach of uncertainty quantification using such polynomial expansions is however intrusive. It is based on a Galerkin-type projection formulation of the model equations to derive the governing equations for the polynomial expansion coefficients of the output quantities of interest. Both the intrusive and non-intrusive approaches call for the computation of third-order, even fourth-order momen...
Symbolic Algebra Development for Higher-Order Electron Propagator Formulation and Implementation.
Tamayo-Mendoza, Teresa; Flores-Moreno, Roberto
2014-06-10
Through the use of symbolic algebra, implemented in a program, the algebraic expression of the elements of the self-energy matrix for the electron propagator to different orders were obtained. In addition, a module for the software package Lowdin was automatically generated. Second- and third-order electron propagator results have been calculated to test the correct operation of the program. It was found that the Fortran 90 modules obtained automatically with our algorithm succeeded in calculating ionization energies with the second- and third-order electron propagator in the diagonal approximation. The strategy for the development of this symbolic algebra program is described in detail. This represents a solid starting point for the automatic derivation and implementation of higher-order electron propagator methods.
Scott, Kristin M; Barbarin, Oscar A; Brown, Jeffrey M
2013-01-01
This study examines the relations of higher order (i.e., abstract) thinking (HOT) skills to specific domains of social competence in Black boys (n = 108) attending publicly sponsored prekindergarten (pre-K) programs. Data for the study were collected as part of the National Center for Early Development and Learning (NCEDL) Multi-State Study, a national, longitudinal study examining the quality and outcomes in a representative sample of publicly sponsored pre-K programs in six states (N = 240). Pre-K and kindergarten teachers rated randomly selected children on measures of abstract thinking, self-regulation, and social functioning at the beginning and end of each school year. Applying structural equation modeling, compared with earlier time points, HOT measured in the fall of kindergarten significantly predicted each of the domains of social competence in the spring of kindergarten, with the exception of peer social skills, while controlling for general cognitive ability. Results suggest that early intervention to improve HOT may be an effective and more focused approach to address concerns about Black boys' early social competencies in specific domains and potentially reduce the risk of later social difficulties. © 2013 American Orthopsychiatric Association.
Higher-order neural network software for distortion invariant object recognition
Reid, Max B.; Spirkovska, Lilly
1991-01-01
The state-of-the-art in pattern recognition for such applications as automatic target recognition and industrial robotic vision relies on digital image processing. We present a higher-order neural network model and software which performs the complete feature extraction-pattern classification paradigm required for automatic pattern recognition. Using a third-order neural network, we demonstrate complete, 100 percent accurate invariance to distortions of scale, position, and in-plate rotation. In a higher-order neural network, feature extraction is built into the network, and does not have to be learned. Only the relatively simple classification step must be learned. This is key to achieving very rapid training. The training set is much smaller than with standard neural network software because the higher-order network only has to be shown one view of each object to be learned, not every possible view. The software and graphical user interface run on any Sun workstation. Results of the use of the neural software in autonomous robotic vision systems are presented. Such a system could have extensive application in robotic manufacturing.
A Higher-Order Neural Network Design for Improving Segmentation Performance in Medical Image Series
Selvi, Eşref; Selver, M. Alper; Güzeliş, Cüneyt; Dicle, Oǧuz
2014-03-01
Segmentation of anatomical structures from medical image series is an ongoing field of research. Although, organs of interest are three-dimensional in nature, slice-by-slice approaches are widely used in clinical applications because of their ease of integration with the current manual segmentation scheme. To be able to use slice-by-slice techniques effectively, adjacent slice information, which represents likelihood of a region to be the structure of interest, plays critical role. Recent studies focus on using distance transform directly as a feature or to increase the feature values at the vicinity of the search area. This study presents a novel approach by constructing a higher order neural network, the input layer of which receives features together with their multiplications with the distance transform. This allows higher-order interactions between features through the non-linearity introduced by the multiplication. The application of the proposed method to 9 CT datasets for segmentation of the liver shows higher performance than well-known higher order classification neural networks.
Multifunctional diffractive optical elements for the generation of higher order Bessel-like-beams
Vijayakumar, A.; Bhattacharya, Shanti
2015-01-01
Higher Order Bessel Beams (HOBBs) have many useful applications in optical trapping experiments. The generation of HOBBs is achieved by illuminating an axicon by a Laguerre-Gaussian beam generated by a spiral phase plate. It can also be generated by a Holographic Optical Element (HOE) containing the functions of the Spiral Phase Plate (SPP) and an axicon. However the HOBB's large focal depth reduces the intensity at each plane. In this paper, we propose a multifunctional Diffractive Optical Element (DOE) containing the functions of a SPP, axicon and a Fresnel Zone Lens (FZL) to generate higher efficiency higher order Bessel-like-beams with a reduced focal depth. The functions of a SPP and a FZL were combined by shifting the location of zones of FZL in a spiral fashion. The resulting element is combined with an axicon by modulo-2π phase addition technique. The final composite element contains the functions of SPP, FZL and axicon. The elements were designed with different topological charges and fabricated using electron beam direct writing. The elements were tested and the generation of a higher order Bessel-like-beams is confirmed. Besides, the elements also generated high quality donut beams at two planes equidistant from the focal plane of the FZL.
Breast-feeding and bottle-feeding of twins, triplets and higher order multiple births.
Yokoyama, Yoshie; Ooki, Syuichi
2004-11-01
This study was performed to determine the rates of breast-feeding and/or bottle-feeding in mothers of twins, triplets and higher order multiple births compared to those in mothers of singletons, and identify factors associated with decision as to breast-feed or bottle-feed. The subjects were 1,529 mothers of twins aged 6 months-6 years and 258 mothers of triplets and higher order multiple births (higher multiples) aged 6 months-6 years (234 mothers of triplets, 20 mothers of quadruplets, 4 mothers of quintuplets). Also, 1,300 subjects were recruited as a control group from mothers of singletons aged 6 months-6 years. Information regarding feeding methods, including exclusive breast-feeding, mixed-feeding and bottle-feeding with formula milk only, and duration of breast-feeding (in months) was collected. There were significantly higher rates of bottle-feeding in mothers of twins and higher multiples than in mothers of singletons. Duration of breast-feeding in mothers who chose exclusive breast-feeding or mixed-feeding for twins and higher multiples was significantly shorter than those for the singletons. The feeding methods for the twins or higher multiples were not associated with prematurity or low birth weight. However, after adjusting for each associated factor using logistic regression analysis, the decision to bottle-feed was significantly associated with non-cooperation of the husband in childrearing and degree of anxiety that mothers felt when informed of a multiple pregnancy. The odds ratio indicated that mothers who received no cooperation from the husband for childrearing were 1.83 times more likely to choose bottle-feeding as those who received cooperation. Further, the odds ratio indicated that mothers who felt greater anxiety when informed of a multiple pregnancy were 1.73 times more likely to choose bottle-feeding as those who did not feel much anxiety. This study found that establishment and continuation of breast-feeding for twins, triplets and
Kulig, Alan W; Blanchard, Rebecca D
2016-07-01
It is difficult to assess applicants' higher-order cognitive thinking skills during conventional resident interviews. Application metrics currently employed are useful indicators of academic and personal success in targeted areas, yet value of this information in predicting future clinical performance is limited. We developed an assessment tool to evaluate higher-order cognitive function in real time during anesthesiology resident applicant interviews. During the 2014-2015 residency interview season, we integrated simulation training into applicant interviews to evaluate higher-order cognitive skills. Our 5-minute simulation emphasized the Team STEPPS 2-Challenge Rule and explored candidates' critical thinking, analytical decision making, and response to stress. Participating applicants were evaluated using an outcomes-based checklist targeting desired responses. We also sent applicants a post-National Resident Matching Program survey to assess their perceptions of the simulation's value and educational utility. A total of 90 applicants (75% of all applicants) participated in the simulation, which taught residents about important patient safety concepts and provided the program with real time information about their critical thinking ability. All applicants were confident or very confident that they would both speak up and know what to say if they encountered a patient safety breach as a result of participating in this exercise. Simulation performance affected desirability status for 35% of participating applicants, where 23% of applicants ranked higher, and 12% ranked lower compared to baseline application status. Cognitive simulation training was useful in assessing resident applicant higher-order thinking skills and in helping stratify candidates in conjunction with standard application metrics.
Higher-order anisotropies in the blast-wave model: Disentangling flow and density field anisotropies
Energy Technology Data Exchange (ETDEWEB)
Cimerman, Jakub [Czech Technical University in Prague, FNSPE, Prague (Czech Republic); Comenius University, FMPI, Bratislava (Slovakia); Tomasik, Boris [Czech Technical University in Prague, FNSPE, Prague (Czech Republic); Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia); Csanad, Mate; Loekoes, Sandor [Eoetvoes Lorand University, Budapest (Hungary)
2017-08-15
We formulate a generalisation of the blast-wave model which is suitable for the description of higher-order azimuthal anisotropies of the hadron production. The model includes anisotropy in the density profile as well as an anisotropy in the transverse expansion velocity field. We then study how these two kinds of anisotropies influence the single-particle distributions and the correlation radii of two-particle correlation functions. Particularly we focus on the third-order anisotropy and consideration is given averaging over different orientations of the event plane. (orig.)
PHz-Wide Spectral Interference Through Coherent Plasma-Induced Fission of Higher-Order Solitons
Köttig, F.; Tani, F.; Travers, J. C.; Russell, P. St. J.
2017-06-01
We identify a novel regime of soliton-plasma interactions in which high-intensity ultrashort pulses of intermediate soliton order undergo coherent plasma-induced fission. Experimental results obtained in gas-filled hollow-core photonic crystal fiber are supported by rigorous numerical simulations. In the anomalous dispersion regime, the cumulative blueshift of higher-order input solitons with ionizing intensities results in pulse splitting before the ultimate self-compression point, leading to the generation of robust pulse pairs with PHz bandwidths. The novel dynamics closes the gap between plasma-induced adiabatic soliton compression and modulational instability.
Higher Order, Hybrid BEM/FEM Methods Applied to Antenna Modeling
Fink, P. W.; Wilton, D. R.; Dobbins, J. A.
2002-01-01
In this presentation, the authors address topics relevant to higher order modeling using hybrid BEM/FEM formulations. The first of these is the limitation on convergence rates imposed by geometric modeling errors in the analysis of scattering by a dielectric sphere. The second topic is the application of an Incomplete LU Threshold (ILUT) preconditioner to solve the linear system resulting from the BEM/FEM formulation. The final tOpic is the application of the higher order BEM/FEM formulation to antenna modeling problems. The authors have previously presented work on the benefits of higher order modeling. To achieve these benefits, special attention is required in the integration of singular and near-singular terms arising in the surface integral equation. Several methods for handling these terms have been presented. It is also well known that achieving he high rates of convergence afforded by higher order bases may als'o require the employment of higher order geometry models. A number of publications have described the use of quadratic elements to model curved surfaces. The authors have shown in an EFIE formulation, applied to scattering by a PEC .sphere, that quadratic order elements may be insufficient to prevent the domination of modeling errors. In fact, on a PEC sphere with radius r = 0.58 Lambda(sub 0), a quartic order geometry representation was required to obtain a convergence benefi.t from quadratic bases when compared to the convergence rate achieved with linear bases. Initial trials indicate that, for a dielectric sphere of the same radius, - requirements on the geometry model are not as severe as for the PEC sphere. The authors will present convergence results for higher order bases as a function of the geometry model order in the hybrid BEM/FEM formulation applied to dielectric spheres. It is well known that the system matrix resulting from the hybrid BEM/FEM formulation is ill -conditioned. For many real applications, a good preconditioner is required
A higher-order numerical framework for stochastic simulation of chemical reaction systems.
Székely, Tamás
2012-07-15
BACKGROUND: In this paper, we present a framework for improving the accuracy of fixed-step methods for Monte Carlo simulation of discrete stochastic chemical kinetics. Stochasticity is ubiquitous in many areas of cell biology, for example in gene regulation, biochemical cascades and cell-cell interaction. However most discrete stochastic simulation techniques are slow. We apply Richardson extrapolation to the moments of three fixed-step methods, the Euler, midpoint and θ-trapezoidal τ-leap methods, to demonstrate the power of stochastic extrapolation. The extrapolation framework can increase the order of convergence of any fixed-step discrete stochastic solver and is very easy to implement; the only condition for its use is knowledge of the appropriate terms of the global error expansion of the solver in terms of its stepsize. In practical terms, a higher-order method with a larger stepsize can achieve the same level of accuracy as a lower-order method with a smaller one, potentially reducing the computational time of the system. RESULTS: By obtaining a global error expansion for a general weak first-order method, we prove that extrapolation can increase the weak order of convergence for the moments of the Euler and the midpoint τ-leap methods, from one to two. This is supported by numerical simulations of several chemical systems of biological importance using the Euler, midpoint and θ-trapezoidal τ-leap methods. In almost all cases, extrapolation results in an improvement of accuracy. As in the case of ordinary and stochastic differential equations, extrapolation can be repeated to obtain even higher-order approximations. CONCLUSIONS: Extrapolation is a general framework for increasing the order of accuracy of any fixed-step stochastic solver. This enables the simulation of complicated systems in less time, allowing for more realistic biochemical problems to be solved.
Experimental investigations of higher-order springing and whipping-WILS project
Directory of Open Access Journals (Sweden)
Hong Sa Young
2014-12-01
Full Text Available Springing and whipping are becoming increasingly important considerations in ship design as container ships increase in size. In this study, the springing and whipping characteristics of a large container ship were investigated through a series of systematic model tests in waves. A multi-segmented hull model with a backbone was adopted for measurement of springing and whipping signals. A conversion method for extracting torsion springing and whipping is described in this paper for the case of an open-section backbone. Higher-order springing, higher-mode torsion responses, and the effects of linear and nonlinear springing in irregular waves are highlighted in the discussion.
Nanoscale constrictions in superconducting coplanar waveguide resonators
Energy Technology Data Exchange (ETDEWEB)
Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando, E-mail: fluis@unizar.es [Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, 50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Sesé, Javier [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Atkinson, James; Barco, Enrique del [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Sánchez-Azqueta, Carlos [Dpto. de Ingeniería Electrónica y Telecomunicaciones, Universidad de Zaragoza, 50009 Zaragoza (Spain); Majer, Johannes [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna (Austria)
2014-10-20
We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.
Study of Higher Order Modes in Superconducting Accelerating Structures for Linac Applications
Schuh, Marcel; Welsch, C P
2011-01-01
Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor and complex pulse structure. Therefore, the full HOM spectrum has to be analysed in detail to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam dynamics simulation code, Simulation of higher order Mode Dynamics (SMD), focusing on beam-HOM interaction, has been developed in the frame of this project. SMD allows to analyse the beam behaviour under the presence of HOMs, taking into account many important effects, such as for example the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. SMD is used to investigate in detail into the effects of HOMs in the Superconducting Proton Linac (SPL) at CERN and in particular their potential to drive beam instabili- ties in the longitudinal and transverse direction. Based...
Robust rooftop extraction from visible band images using higher order CRF
Li, Er
2015-08-01
In this paper, we propose a robust framework for building extraction in visible band images. We first get an initial classification of the pixels based on an unsupervised presegmentation. Then, we develop a novel conditional random field (CRF) formulation to achieve accurate rooftops extraction, which incorporates pixel-level information and segment-level information for the identification of rooftops. Comparing with the commonly used CRF model, a higher order potential defined on segment is added in our model, by exploiting region consistency and shape feature at segment level. Our experiments show that the proposed higher order CRF model outperforms the state-of-the-art methods both at pixel and object levels on rooftops with complex structures and sizes in challenging environments. © 1980-2012 IEEE.
Energy Technology Data Exchange (ETDEWEB)
John, V.; Matthies, G.; Tobiska, L. [Magdeburg Univ. (Germany). Inst. fuer Analysis und Numerik
2001-07-01
For solving complex three-dimensional flow problems, many different approaches have been developed. It turns out that both the discretization concept and the solver designed for the discrete problem influences essentially the accuracy and efficiency of the method. The main objective of the paper is to compare lower and higher order finite element discretizations for the accurate and fast solution of the incompressible Navier-Stokes equation in three space dimensions. To this end, a well-defined benchmark problem of a channel flow around an obstacle is used to quantify the gain in accuracy when higher order discretizations are used. The comparison covers also the robust and efficient solution of the discretized algebraic equations. (orig.)
Enhancing Higher Order Thinking Skills Among Inservice Science Teachers Via Embedded Assessment
Barak, Miri; Dori, Yehudit Judy
2009-10-01
Testing students on higher order thinking skills may reinforce these skills among them. To research this assertion, we developed a graduate course for inservice science teachers in a framework of a “Journal Club”—a hybrid course which combines face-to-face classroom discussions with online activities, interrelating teaching, learning, and assessment. The course involves graduate students in critical evaluation of science education articles and cognitive debates, and tests them on these skills. Our study examined the learning processes and outcomes of 51 graduate students, from three consecutive semesters. Findings indicated that the students’ higher order thinking skills were enhanced in terms of their ability to (a) pose complex questions, (b) present solid opinions, (c) introduce consistent arguments, and (d) demonstrate critical thinking.
Benchmark experiments for higher-order and full-Stokes ice sheet models (ISMIP–HOM
Directory of Open Access Journals (Sweden)
F. Pattyn
2008-08-01
Full Text Available We present the results of the first ice sheet model intercomparison project for higher-order and full-Stokes ice sheet models. These models are compared and verified in a series of six experiments of which one has an analytical solution obtained from a perturbation analysis. The experiments are applied to both 2-D and 3-D geometries; five experiments are steady-state diagnostic, and one has a time-dependent prognostic solution. All participating models give results that are in close agreement. A clear distinction can be made between higher-order models and those that solve the full system of equations. The full-Stokes models show a much smaller spread, hence are in better agreement with one another and with the analytical solution.
Direct Amplitude-Phase Near-Field Observation of Higher-Order Anapole States.
Zenin, Vladimir A; Evlyukhin, Andrey B; Novikov, Sergey M; Yang, Yuanqing; Malureanu, Radu; Lavrinenko, Andrei V; Chichkov, Boris N; Bozhevolnyi, Sergey I
2017-11-08
Anapole states associated with the resonant suppression of electric-dipole scattering exhibit minimized extinction and maximized storage of electromagnetic energy inside a particle. Using numerical simulations, optical extinction spectroscopy, and amplitude-phase near-field mapping of silicon dielectric disks, we demonstrate high-order anapole states in the near-infrared wavelength range (900-1700 nm). We develop the procedure for unambiguously identifying anapole states by monitoring the normal component of the electric near-field and experimentally detect the first two anapole states as verified by far-field extinction spectroscopy and confirmed with the numerical simulations. We demonstrate that higher-order anapole states possess stronger energy concentration and narrower resonances, a remarkable feature that is advantageous for their applications in metasurfaces and nanophotonics components, such as nonlinear higher-harmonic generators and nanoscale lasers.
John Carroll’s Views on Intelligence: Bi-Factor vs. Higher-Order Models
Directory of Open Access Journals (Sweden)
A. Alexander Beaujean
2015-10-01
Full Text Available The development of factor models is inextricably tied to the history of intelligence research. One of the most commonly-cited scholars in the field is John Carroll, whose three-stratum theory of cognitive ability has been one of the most influential models of cognitive ability in the past 20 years. Nonetheless, there is disagreement about how Carroll conceptualized the factors in his model. Some argue that his model is best represented through a higher-order model, while others argue that a bi-factor model is a better representation. Carroll was explicit about what he perceived the best way to represent his model, but his writings are not always easy to understand. In this article, I clarify his position by first describing the details and implications of bi-factor and higher-order models then show that Carroll’s published views are better represented by a bi-factor model.
Albert, Lena; Rottensteiner, Franz; Heipke, Christian
2017-08-01
We propose a new approach for the simultaneous classification of land cover and land use considering spatial as well as semantic context. We apply a Conditional Random Fields (CRF) consisting of a land cover and a land use layer. In the land cover layer of the CRF, the nodes represent super-pixels; in the land use layer, the nodes correspond to objects from a geospatial database. Intra-layer edges of the CRF model spatial dependencies between neighbouring image sites. All spatially overlapping sites in both layers are connected by inter-layer edges, which leads to higher order cliques modelling the semantic relation between all land cover and land use sites in the clique. A generic formulation of the higher order potential is proposed. In order to enable efficient inference in the two-layer higher order CRF, we propose an iterative inference procedure in which the two classification tasks mutually influence each other. We integrate contextual relations between land cover and land use in the classification process by using contextual features describing the complex dependencies of all nodes in a higher order clique. These features are incorporated in a discriminative classifier, which approximates the higher order potentials during the inference procedure. The approach is designed for input data based on aerial images. Experiments are carried out on two test sites to evaluate the performance of the proposed method. The experiments show that the classification results are improved compared to the results of a non-contextual classifier. For land cover classification, the result is much more homogeneous and the delineation of land cover segments is improved. For the land use classification, an improvement is mainly achieved for land use objects showing non-typical characteristics or similarities to other land use classes. Furthermore, we have shown that the size of the super-pixels has an influence on the level of detail of the classification result, but also on the
A finite deformation theory of higher-order gradient crystal plasticity
DEFF Research Database (Denmark)
Kuroda, Mitsutoshi; Tvergaard, Viggo
2008-01-01
For higher-order gradient crystal plasticity, a finite deformation formulation is presented. The theory does not deviate much from the conventional crystal plasticity theory. Only a back stress effect and additional differential equations for evolution of the geometrically necessary dislocation (...... for the small deformation theory. As in a previous formulation for small deformation, the present formulation applies to the context of multiple and three-dimensional slip deformations. (C) 2008 Elsevier Ltd. All rights reserved....
Growth of meromorphic solutions of higher-order linear differential equations
Directory of Open Access Journals (Sweden)
Wenjuan Chen
2009-01-01
Full Text Available In this paper, we investigate the higher-order linear differential equations with meromorphic coefficients. We improve and extend a result of M.S. Liu and C.L. Yuan, by using the estimates for the logarithmic derivative of a transcendental meromorphic function due to Gundersen, and the extended Winman-Valiron theory which proved by J. Wang and H.X. Yi. In addition, we also consider the nonhomogeneous linear differential equations.
Analytical Treatment of Higher-Order Graphs: A Path Ordinal Method for Solving Graphs
Directory of Open Access Journals (Sweden)
Hala Kamal
2017-11-01
Full Text Available Analytical treatment of the composition of higher-order graphs representing linear relations between variables is developed. A path formalism to deal with problems in graph theory is introduced. It is shown how paths in the composed graph representing individual contributions to variables relation can be enumerated and represented by ordinals. The method allows for one to extract partial information and gives an alternative to classical graph approach.
On the mild solutions of higher-order differential equations in Banach spaces
Directory of Open Access Journals (Sweden)
Nguyen Thanh Lan
2003-01-01
Full Text Available For the higher-order abstract differential equation u(n(t=Au(t+f(t, t∈ℝ, we give a new definition of mild solutions. We then characterize the regular admissibility of a translation-invariant subspace ℳ of BUC(ℝ,E with respect to the above-mentioned equation in terms of solvability of the operator equation AX−Xn=C. As applications, periodicity and almost periodicity of mild solutions are also proved.
Higher?order oligomerization promotes localization of SPOP to liquid nuclear speckles
Marzahn, Melissa R.; Marada, Suresh; Lee, Jihun; Nourse, Amanda; Kenrick, Sophia; Zhao, Huaying; Ben?Nissan, Gili; Kolaitis, Regina?Maria; Peters, Jennifer L.; Pounds, Stanley; Errington, Wesley J; Priv?, Gilbert G; Taylor, J Paul; Sharon, Michal; Schuck, Peter
2016-01-01
Abstract Membrane?less organelles in cells are large, dynamic protein/protein or protein/RNA assemblies that have been reported in some cases to have liquid droplet properties. However, the molecular interactions underlying the recruitment of components are not well understood. Herein, we study how the ability to form higher?order assemblies influences the recruitment of the speckle?type POZ protein (SPOP) to nuclear speckles. SPOP, a cullin?3?RING ubiquitin ligase (CRL3) substrate adaptor, s...
Learning about the world: developing higher order thinking in music education
Kruger, J.; van der Merwe, L
2012-01-01
Innovative thinking is an innate human capacity geared towards adaptation and survival. Theories of education accordingly aim at developing teaching-learning strategies that promote creative, problem-solving reasoning referred to as higher order thinking. This essay briefly explains some of the assumptions underlying this concept, and then suggests how they may be reconfigured in a strategy suitable for education in and through music. The strategy involves a basic process of analysis...
Higgs boson decay into heavy quarks and heavy leptons: higher order corrections
Kim, Victor T
2010-01-01
Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_H< 2M_W, are briefly reviewed. The effects of higher order perturbative QCD (up to alpha_s^4-level) and QED corrections are considered. The uncertainties of the decay width of Higgs boson into bb and tau+tau- are discussed.
Generalized Green's functions for higher order boundary value matrix differential systems
Directory of Open Access Journals (Sweden)
R. J. Villanueva
1992-01-01
Full Text Available In this paper, a Green's matrix function for higher order two point boundary value differential matrix problems is constructed. By using the concept of rectangular co-solution of certain algebraic matrix equation associated to the problem, an existence condition as well as an explicit closed form expression for the solution of possibly not well-posed boundary value problems is given avoiding the increase of the problem dimension.
Liu, Qun; Jiang, Daqing; Hayat, Tasawar; Ahmad, Bashir
2017-09-01
In this paper, we investigate two stochastic SIR epidemic models with higher order perturbation. For the nonautonomous periodic case of the model, by using Has'minskii's theory of periodic solution, we show that the system has at least one nontrivial positive T-periodic solution. For the system disturbed by both the white noise and telephone noise, we establish sufficient conditions for positive recurrence and the existence of ergodic stationary distribution of the positive solution.
Transition, coexistence, and interaction of vector localized waves arising from higher-order effects
Energy Technology Data Exchange (ETDEWEB)
Liu, Chong [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi’an 710069 (China); Zhao, Li-Chen, E-mail: zhaolichen3@163.com [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Wen-Li [Institute of Modern Physics, Northwest University, Xi’an 710069 (China)
2015-11-15
We study vector localized waves on continuous wave background with higher-order effects in a two-mode optical fiber. The striking properties of transition, coexistence, and interaction of these localized waves arising from higher-order effects are revealed in combination with corresponding modulation instability (MI) characteristics. It shows that these vector localized wave properties have no analogues in the case without higher-order effects. Specifically, compared to the scalar case, an intriguing transition between bright–dark rogue waves and w-shaped–anti-w-shaped solitons, which occurs as a result of the attenuation of MI growth rate to vanishing in the zero-frequency perturbation region, is exhibited with the relative background frequency. In particular, our results show that the w-shaped–anti-w-shaped solitons can coexist with breathers, coinciding with the MI analysis where the coexistence condition is a mixture of a modulation stability and MI region. It is interesting that their interaction is inelastic and describes a fusion process. In addition, we demonstrate an annihilation phenomenon for the interaction of two w-shaped solitons which is identified essentially as an inelastic collision in this system. -- Highlights: •Vector rogue wave properties induced by higher-order effects are studied. •A transition between vector rogue waves and solitons is obtained. •The link between the transition and modulation instability (MI) is demonstrated. •The coexistence of vector solitons and breathers coincides with the MI features. •An annihilation phenomenon for the vector two w-shaped solitons is presented.
Yıgıt, Gülsemay; Bayram, Mustafa
2017-01-01
In this study linear and nonlinear higher order singularly perturbed problems are examined by a numerical approach, the differential quadrature method. Here, the main idea is using Chebyshev polynomials to acquire the weighting coefficient matrix which is necessary to get numerical results. Following this, different class of perturbation problems are considered as test problems. Then, all results are shown in tables and also comparison between numerical and exact solution shows the accuracy a...
What Do Trainers Need to Know to Train Higher-Order Thinking Skills
2017-11-01
and Training website http://www.ica-sae.org/trainer/ english /p9.htm Cruickshank, D., Jenkins, D., & Metcalf, K. (2011). The Act of Teaching ...instance, there is a movement in American secondary education to develop higher-order thinking skills ( Teach for America, 2011). A number of classroom...common educational goal ( Teach for America, 2011). However, secondary education has historically relied on techniques that elicit and develop lower
Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.
Burke, Tina M; Scheer, Frank A J L; Ronda, Joseph M; Czeisler, Charles A; Wright, Kenneth P
2015-08-01
Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep. © 2015 European Sleep Research Society.
Strategy-effects in prefrontal cortex during learning of higher-order S-R rules.
Wolfensteller, Uta; von Cramon, D Yves
2011-07-15
All of us regularly face situations that require the integration of the available information at hand with the established rules that guide behavior in order to generate the most appropriate action. But where individuals differ from one another is most certainly in terms of the different strategies that are adopted during this process. A previous study revealed differential brain activation patterns for the implementation of well established higher-order stimulus-response (S-R) rules depending on inter-individual strategy differences (Wolfensteller and von Cramon, 2010). This raises the question of how these strategies evolve or which neurocognitive mechanisms underlie these inter-individual strategy differences. Using functional magnetic resonance imaging (fMRI), the present study revealed striking strategy-effects across regions of the lateral prefrontal cortex during the implementation of higher-order S-R rules at an early stage of learning. The left rostrolateral prefrontal cortex displayed a quantitative strategy-effect, such that activation during rule integration based on a mismatch was related to the degree to which participants continued to rely on rule integration. A quantitative strategy ceiling effect was observed for the left inferior frontal junction area. Conversely, the right inferior frontal gyrus displayed a qualitative strategy-effect such that participants who at a later point relied on an item-based strategy showed stronger activations in this region compared to those who continued with the rule integration strategy. Together, the present findings suggest that a certain amount of rule integration is mandatory when participants start to learn higher-order rules. The more efficient item-based strategy that evolves later appears to initially require the recruitment of additional cognitive resources in order to shield the currently relevant S-R association from interfering information. Copyright © 2011 Elsevier Inc. All rights reserved.
Time-discrete higher order ALE formulations: a priori error analysis
Bonito, Andrea
2013-03-16
We derive optimal a priori error estimates for discontinuous Galerkin (dG) time discrete schemes of any order applied to an advection-diffusion model defined on moving domains and written in the Arbitrary Lagrangian Eulerian (ALE) framework. Our estimates hold without any restrictions on the time steps for dG with exact integration or Reynolds\\' quadrature. They involve a mild restriction on the time steps for the practical Runge-Kutta-Radau methods of any order. The key ingredients are the stability results shown earlier in Bonito et al. (Time-discrete higher order ALE formulations: stability, 2013) along with a novel ALE projection. Numerical experiments illustrate and complement our theoretical results. © 2013 Springer-Verlag Berlin Heidelberg.
Directory of Open Access Journals (Sweden)
Ahmad Bashir
2010-01-01
Full Text Available We study an initial value problem for a coupled Caputo type nonlinear fractional differential system of higher order. As a first problem, the nonhomogeneous terms in the coupled fractional differential system depend on the fractional derivatives of lower orders only. Then the nonhomogeneous terms in the fractional differential system are allowed to depend on the unknown functions together with the fractional derivative of lower orders. Our method of analysis is based on the reduction of the given system to an equivalent system of integral equations. Applying the nonlinear alternative of Leray-Schauder, we prove the existence of solutions of the fractional differential system. The uniqueness of solutions of the fractional differential system is established by using the Banach contraction principle. An illustrative example is also presented.
Solving moving interface problems using a higher order accurate finite difference scheme
Mittal, H. V. R.; Ray, Rajendra K.
2017-07-01
A new finite difference scheme is applied to solve partial differential equations in domains with discontinuities due to the presence of time dependent moving or deforming interfaces. This scheme is an extension of the finite difference idea developed for solving incompressible, steady stokes equations in discontinuous domains with fixed interfaces [1]. This new idea is applied at the irregular points at each time step in conjunction with the Crank-Nicolson (CN) implicit scheme and a recently developed Higher Order Compact (HOC) scheme at regular points. For validation, Stefan's problem is considered with a moving interface in one dimension. In two dimensions, heat equation is considered on a square domain with a circular interface whose radius is continuously changing with time. HOC scheme is found to produce better results and the order of accuracy is slightly better than that of the CN scheme. However, both the schemes show around second order accuracy and good agreement with the analytical solution.
Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study
AUTHOR|(CDS)2085329; Gerigk, Frank; Van Rienen, Ursula
2017-01-01
Higher order modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.
Energy Technology Data Exchange (ETDEWEB)
Guessous, N. E-mail: guessous_najib@hotmail.com; Akhmouch, M
2002-10-01
A higher analytical nodal method for the multigroup neutron diffusion equations, based on the transverse integration procedure, is presented. The discrete 1D equations are cast with the interface partial current techniques in response matrix formalism. The remaining Legendre coefficients of the transverse leakage moment are determined exactly in terms of the different neutron flux moments order in the reference node. In the weighted balance equations, the transverse leakage moments are linearly written in terms of the partial currents, facial and centered fluxes moments. The self-consistent is guaranteed. Furthermore, as the order k increase the neutronic balance in each node and the copulate between the adjacent cell are reinforced. The convergence order in L{sup 2}-norm is of O(h{sup k+3-{delta}k{sub 0}}) under smooth assumptions. The efficacy of the method is showed for 2D-PWR, 2D-IAEA LWR and 2D-LMFBR benchmark problems.
Educating Grade 6 students for higher-order thinking and its influence on creativity
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Wajeeh Daher
2017-04-01
Full Text Available Educating students for higher-order thinking provides them with tools that turn them into more critical thinkers. This supports them in overcoming life problems that they encounter, as well as becoming an integral part of the society. This students’ education is attended to by educational organisations that emphasise the positive consequences of educating students for higher-order thinking, including creative thinking. One way to do that is through educational programmes that educate for higher-order thinking. One such programme is the Cognitive Research Trust (CoRT thinking programme. The present research intended to examine the effect of the participation of Grade 6 students in a CoRT programme on their creative thinking. Fifty-three students participated in the research; 27 participated in a CoRT programme, while 26 did not participate in such programme. The ANCOVA test showed that the students who participated in the CoRT programme outperformed significantly, in creative thinking, the students who did not. Moreover, the students in the CoRT programme whose achievement scores were between 86 and 100 outperformed significantly the other achievement groups of students. Furthermore, students with reported high ability outperformed significantly the other ability groups of students. The results did not show statistically significant differences in students’ creativity attributed to gender.
Purposely Teaching for the Promotion of Higher-order Thinking Skills: A Case of Critical Thinking
Miri, Barak; David, Ben-Chaim; Uri, Zoller
2007-10-01
This longitudinal case-study aimed at examining whether purposely teaching for the promotion of higher order thinking skills enhances students’ critical thinking (CT), within the framework of science education. Within a pre-, post-, and post-post experimental design, high school students, were divided into three research groups. The experimental group ( n = 57) consisted of science students who were exposed to teaching strategies designed for enhancing higher order thinking skills. Two other groups: science ( n = 41) and non-science majors ( n = 79), were taught traditionally, and acted as control. By using critical thinking assessment instruments, we have found that the experimental group showed a statistically significant improvement on critical thinking skills components and disposition towards critical thinking subscales, such as truth-seeking, open-mindedness, self-confidence, and maturity, compared with the control groups. Our findings suggest that if teachers purposely and persistently practice higher order thinking strategies for example, dealing in class with real-world problems, encouraging open-ended class discussions, and fostering inquiry-oriented experiments, there is a good chance for a consequent development of critical thinking capabilities.
Compositional modeling of three-phase flow with gravity using higher-order finite element methods
Moortgat, Joachim
2011-05-11
A wide range of applications in subsurface flow involve water, a nonaqueous phase liquid (NAPL) or oil, and a gas phase, such as air or CO2. The numerical simulation of such processes is computationally challenging and requires accurate compositional modeling of three-phase flow in porous media. In this work, we simulate for the first time three-phase compositional flow using higher-order finite element methods. Gravity poses complications in modeling multiphase processes because it drives countercurrent flow among phases. To resolve this issue, we propose a new method for the upwinding of three-phase mobilities. Numerical examples, related to enhanced oil recovery and carbon sequestration, are presented to illustrate the capabilities of the proposed algorithm. We pay special attention to challenges associated with gravitational instabilities and take into account compressibility and various phase behavior effects, including swelling, viscosity changes, and vaporization. We find that the proposed higher-order method can capture sharp solution discontinuities, yielding accurate predictions of phase boundaries arising in computational three-phase flow. This work sets the stage for a broad extension of the higher-order methods for numerical simulation of three-phase flow for complex geometries and processes.
High temperature sensing using higher-order-mode rejected sapphire-crystal fiber gratings
Zhan, Chun; Kim, Jae Hun; Lee, Jon; Yin, Stuart; Ruffin, Paul; Luo, Claire
2007-09-01
In this paper, we report the fabrication of higher-order-mode rejected fiber Bragg gratings (FBGs) in sapphire crystal fiber using infrared (IR) femtosecond laser illumination. The grating is tested in high temperature furnace up to 1600 degree Celsius. As sapphire fiber is only available as highly multimode fiber, a scheme to filter out higher order modes in favor for the fundamental mode is theoretically evaluated and experimentally demonstrated. The approach is to use an ultra thin sapphire crystal fiber (60 micron in diameter) to decrease the number of modes. The small diameter fiber also enables bending the fiber to certain radius which is carefully chosen to provide low loss for the fundamental mode LP01 and high loss for the other high-order modes. After bending, less-than-2-nm resonant peak bandwidth is achieved. The grating spectrum is improved, and higher resolution sensing measurement can be achieved. This mode filtering method is very easy to implement. Furthermore, the sapphire fiber is sealed with hi-purity alumina ceramic cement inside a flexible high temperature titanium tube, and the highly flexible titanium tube offers a robust packaging to sapphire fiber. Our high temperature sapphire grating sensor is very promising in extremely high temperature sensing application.
Higher-order social cognition in first-episode major depression.
Ladegaard, Nicolai; Larsen, Erik Roj; Videbech, Poul; Lysaker, Paul H
2014-04-30
Patients suffering from major depression experience difficulties in multiple cognitive faculties. A growing body of research has linked affective disorders to abnormalities in social cognition and specifically the processing of discrete emotional stimuli. However, little inquiry has gone into possible impairment in higher-order social cognition including theory of mind, social perception and metacognition. Forty-four medication-naïve patients with first-episode unipolar major depressive disorder and an equal number of matched controls were assessed by the Metacognitive Assessment Scale-Abbreviated (MAS-A), The Frith-Happé animations (FHA) and The Awareness of Social Inference Test (TASIT). Additionally, neurocognition was assessed utilyzing the Cambridge Neuropsychological Test Automated Battery (CANTAB). Depressed patients showed impairment in all domains of higher-order social cognitive ability. Importantly, social cognitive variables retained their inter-group significance after controlling for possible covariates including neurocognition. Results indicate that first-episode depressed patients experience difficulties in all domains of higher-order social cognition including theory of mind, social perception and metacognition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Generalized higher order two-point moments in turbulent boundary layers.
Yang, Xiang; Marusic, Ivan; Meneveau, Charles
2015-11-01
Generalized higher order two-point moments such as uz'm (x) uz'n(x + r > 2 / (m + n) and uz'2 (x) -uz'2 (x + r) ] n > 1 / n (where z is the distance from the wall, r is the distance in the flow direction, and m and n are arbitrary integers) are examined using high Reynolds number experimental data in turbulent boundary layer flow. Logarithmic behaviors with respect to both s and z in such statistics are observed. Certain predictions for such generalized log laws can be made in the context of the attached eddy hypothesis. Particularly simple results can be obtained for the scaling if one considers the velocity fluctuations at some point x and height z being the outcome of a random additive process, e.g. uN' =∑i= 1 Nai , where Ndepends on the wall normal distance zas N ~log (δ / z) , and the ai's are identical independent random additives. Predictions can be made of the slopes in the generalized log laws and these can be compared to the experimental data. For instance, already for single point higher-order moments it was known that the model overpredicts some slopes, indicating a sub-Gaussian behavior in the statistics. Gaussian behavior is rooted in the assumption of independency in ai's. We discuss some variants that introduce correlations, and provide evidence that the generalized higher order two-point moments can help discriminate among various possible models.
Howe, George W; Hornberger, Anna P; Weihs, Karen; Moreno, Francisco; Neiderhiser, Jenae M
2012-05-01
Recent work on comorbidity finds evidence for hierarchical structure of mood and anxiety disorders and symptoms. This study tests whether a higher-order internalizing factor accounts for variation in depression and anxiety symptom severity and change over time in a sample experiencing a period of major life stress. Data on symptoms of depression, chronic worry, and social anxiety were collected five times across seven months from 426 individuals who had recently lost jobs. Growth models for each type of symptom found significant variation in individual trajectories. Slopes were highly correlated across symptom type, as were intercepts. Multilevel confirmatory factor analyses found evidence for a higher-order internalizing factor for both slopes and intercepts, reflective of comorbidity of depression and anxiety, with the internalizing factor accounting for 54% to 91% of the variance in slopes and intercepts of specific symptom sets, providing evidence for both a general common factor and domain-specific factors characterizing level and change in symptoms. Loadings on the higher order factors differed modestly for men and women, and when comparing African American and White participants, but did not differ by age, education, or history of depression. More distal factors including gender and history of depression were strongly associated with internalizing in the early weeks after job loss, but rates of change in internalizing were associated most strongly with reemployment. Findings suggest that stressors may contribute in different ways to the common internalizing factor as compared to variance in anxiety and depression that is independent of that factor.
Alamia, Andrea; Solopchuk, Oleg; D'Ausilio, Alessandro; Van Bever, Violette; Fadiga, Luciano; Olivier, Etienne; Zénon, Alexandre
2016-03-01
Because Broca's area is known to be involved in many cognitive functions, including language, music, and action processing, several attempts have been made to propose a unifying theory of its role that emphasizes a possible contribution to syntactic processing. Recently, we have postulated that Broca's area might be involved in higher-order chunk processing during implicit learning of a motor sequence. Chunking is an information-processing mechanism that consists of grouping consecutive items in a sequence and is likely to be involved in all of the aforementioned cognitive processes. Demonstrating a contribution of Broca's area to chunking during the learning of a nonmotor sequence that does not involve language could shed new light on its function. To address this issue, we used offline MRI-guided TMS in healthy volunteers to disrupt the activity of either the posterior part of Broca's area (left Brodmann's area [BA] 44) or a control site just before participants learned a perceptual sequence structured in distinct hierarchical levels. We found that disruption of the left BA 44 increased the processing time of stimuli representing the boundaries of higher-order chunks and modified the chunking strategy. The current results highlight the possible role of the left BA 44 in building up effector-independent representations of higher-order events in structured sequences. This might clarify the contribution of Broca's area in processing hierarchical structures, a key mechanism in many cognitive functions, such as language and composite actions.
Higher-order oligomerization targets plasma membrane proteins and HIV gag to exosomes.
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Yi Fang
2007-06-01
Full Text Available Exosomes are secreted organelles that have the same topology as the cell and bud outward (outward is defined as away from the cytoplasm from endosome membranes or endosome-like domains of plasma membrane. Here we describe an exosomal protein-sorting pathway in Jurkat T cells that selects cargo proteins on the basis of both higher-order oligomerization (the oligomerization of oligomers and plasma membrane association, acts on proteins seemingly without regard to their function, sequence, topology, or mechanism of membrane association, and appears to operate independently of class E vacuolar protein-sorting (VPS function. We also show that higher-order oligomerization is sufficient to target plasma membrane proteins to HIV virus-like particles, that diverse Gag proteins possess exosomal-sorting information, and that higher-order oligomerization is a primary determinant of HIV Gag budding/exosomal sorting. In addition, we provide evidence that both the HIV late domain and class E VPS function promote HIV budding by unexpectedly complex, seemingly indirect mechanisms. These results support the hypothesis that HIV and other retroviruses are generated by a normal, nonviral pathway of exosome biogenesis.
Quantum Noether identities for non-local transformations in higher-order derivatives theories
Li, Z P
2003-01-01
Based on the phase-space generating functional of the Green function for a system with a regular/singular higher-order Lagrangian, the quantum canonical Noether identities (NIs) under a local and non-local transformation in phase space have been deduced, respectively. For a singular higher-order Lagrangian, one must use an effective canonical action I sub e sub f sub f sup P in quantum canonical NIs instead of the classical I sup P in classical canonical NIs. The quantum NIs under a local and non-local transformation in configuration space for a gauge-invariant system with a higher-order Lagrangian have also been derived. The above results hold true whether or not the Jacobian of the transformation is equal to unity or not. It has been pointed out that in certain cases the quantum NIs may be converted to conservation laws at the quantum level. This algorithm to derive the quantum conservation laws is significantly different from the quantum first Noether theorem. The applications of our formulation to the Yan...
Simulation and mitigation of higher-order ionospheric errors in PPP
Zus, Florian; Deng, Zhiguo; Wickert, Jens
2017-04-01
We developed a rapid and precise algorithm to compute ionospheric phase advances in a realistic electron density field. The electron density field is derived from a plasmaspheric extension of the International Reference Ionosphere (Gulyaeva and Bilitza, 2012) and the magnetic field stems from the International Geomagnetic Reference Field. For specific station locations, elevation and azimuth angles the ionospheric phase advances are stored in a look-up table. The higher-order ionospheric residuals are computed by forming the standard linear combination of the ionospheric phase advances. In a simulation study we examine how the higher-order ionospheric residuals leak into estimated station coordinates, clocks, zenith delays and tropospheric gradients in precise point positioning. The simulation study includes a few hundred globally distributed stations and covers the time period 1990-2015. We take a close look on the estimated zenith delays and tropospheric gradients as they are considered a data source for meteorological and climate related research. We also show how the by product of this simulation study, the look-up tables, can be used to mitigate higher-order ionospheric errors in practise. Gulyaeva, T.L., and Bilitza, D. Towards ISO Standard Earth Ionosphere and Plasmasphere Model. In: New Developments in the Standard Model, edited by R.J. Larsen, pp. 1-39, NOVA, Hauppauge, New York, 2012, available at https://www.novapublishers.com/catalog/product_info.php?products_id=35812
Predicting early academic achievement: The role of higher-versus lower-order personality traits
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Zupančič Maja
2011-01-01
Full Text Available The study explored the role of children’s (N = 193 individual differences and parental characteristics at the beginning of the first year of schooling in predicting students’ attainment of academic standards at the end of the year. Special attention was paid to children’s personality as perceived by the teachers’ assistants. Along with parents’ education, parenting practices and first-graders’ cognitive ability, the incremental predictive power of children’s higher-order (robust personality traits was compared to the contribution of lower-order (specific traits in explaining academic achievement. The specific traits provided a somewhat more accurate prediction than the robust traits. Unique contributions of maternal authoritative parenting, children’s cognitive ability, and personality to academic achievement were established. The ratings of first-graders’ conscientiousness (a higher-order trait improved the prediction of academic achievement based on parenting and cognitive ability by 12%, whereas assistant teacher’s perceived children’s intelligence and low antagonism (lower-order traits improved the prediction by 17%.
A higher order space-time Galerkin scheme for time domain integral equations
Pray, Andrew J.
2014-12-01
Stability of time domain integral equation (TDIE) solvers has remained an elusive goal formany years. Advancement of this research has largely progressed on four fronts: 1) Exact integration, 2) Lubich quadrature, 3) smooth temporal basis functions, and 4) space-time separation of convolutions with the retarded potential. The latter method\\'s efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was previously reported for first-order surface descriptions (flat elements) and zeroth-order functions as the temporal basis. In this work, we develop the methodology necessary to extend the scheme to higher order surface descriptions as well as to enable its use with higher order basis functions in both space and time. These basis functions are then used in a space-time Galerkin framework. A number of results are presented that demonstrate convergence in time. The viability of the space-time separation method in producing stable results is demonstrated experimentally for these examples.
Exner, Pavel
2015-01-01
This monograph explains the theory of quantum waveguides, that is, dynamics of quantum particles confined to regions in the form of tubes, layers, networks, etc. The focus is on relations between the confinement geometry on the one hand and the spectral and scattering properties of the corresponding quantum Hamiltonians on the other. Perturbations of such operators, in particular, by external fields are also considered. The volume provides a unique summary of twenty five years of research activity in this area and indicates ways in which the theory can develop further. The book is fairly self-contained. While it requires some broader mathematical physics background, all the basic concepts are properly explained and proofs of most theorems are given in detail, so there is no need for additional sources. Without a parallel in the literature, the monograph by Exner and Kovarik guides the reader through this new and exciting field.
Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams
Alcheikh, Nouha
2016-05-06
This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped-clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. © 2016 IOP Publishing Ltd.
Interaction of laser-cooled $^{87}$Rb atoms with higher order modes of an optical nanofiber
Kumar, Ravi; Maimaiti, Aili; Deasy, Kieran; Frawley, Mary C; Chormaic, Síle Nic
2013-01-01
Optical nanofibers can be used to confine light to submicron regions and are very promising for the realization of optical fiber-based quantum networks using cold, neutral atoms. Light propagating in the higher order modes of a nanofiber has a greater evanescent field extension around the waist in comparison with the fundamental mode, leading to a stronger interaction with the surrounding environment. In this work, we report on the integration of a few-mode, optical nanofiber, with a waist diameter of ~700 nm, into a magneto-optical trap for $^{87}$Rb atoms. The nanofiber is fabricated from 80 $\\mu$m diameter fiber using a brushed hydrogen-oxygen flame pulling rig. We show that absorption by laser-cooled atoms around the waist of the nanofiber is stronger when probe light is guided in the higher order modes than in the fundamental mode. As predicted by Masalov and Minogin*, fluorescent light from the atoms coupling in to the nanofiber through the waist has a higher pumping rate (5.8 times) for the higher-orde...
Surface Ordering of Orbitals at a Higher Temperature in LaCoO3 Thin Film
Yamasaki, Yuichi; Fujioka, Jun; Nakao, Hironori; Okamoto, Jun; Sudayama, Takaaki; Murakami, Youichi; Nakamura, Masao; Kawasaki, Masashi; Arima, Takahisa; Tokura, Yoshinori
2016-02-01
We report on the distinct surface state of electronic orders, including spin, orbital, and spin-state degrees of freedom of Co3+ ion, in an epitaxially strained thin film of LaCoO3 grown on (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7 (LSAT) substrate. The surface ordered state was detected by the grazing-incidence resonant soft x-ray scattering at Co L-edge, where the probing depth is less than the topmost 4 nm of surface. Comparing with the result of bulk sensitive x-ray diffraction, we revealed that the transition temperature of the orbital order (spin order) at the surface region is about 30 K (20 K) higher (lower) than that of the bulk. A novel phenomenon of the surface order and bulk disorder of the orbital degree of freedom can be attributed to its collective and lattice-coupled nature which is strongly affected by the translational/inversion symmetry breaking at the surface.
Simon, Nicole A.
Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.
How does participation in inquiry-based activities influence gifted students' higher order thinking?
Reger, Barbara H.
Inquiry-based learning is considered a useful technique to strengthen the critical thinking skills of students. The National Science Standards emphasize its use and the complexities and challenge it provides are well suited for meeting the needs of the gifted. While many studies have documented the effectiveness of this type of instruction, there is a lack of research on growth in higher-order thinking through participation in science inquiry. This study investigated such growth among a small group of gifted fifth-grade students. In this study a group of fifth-grade gifted science students completed a series of three forensics inquiry lessons, and documented questions, ideas and reflections as they constructed evidence to solve a crime. From this class of students, one small group was purposely selected to serve as the focus of the study. Using qualitative techniques, the questions and statements students made as they interacted in the activity were analyzed. Videotaped comments and student logs were coded for emerging patterns and also examined for evidence of increased levels of higher-order thinking based on a rubric that was designed using the six levels of Bloom's Taxonomy. Evidence from this study showed marked increase in and deeper levels of higher-order thinking for two of the students. The other boy and girl showed progress using the inquiry activities, but it was not as evident. The social dynamics of the group seemed to hinder one girl's participation during some of the activities. The social interactions played a role in strengthening the exchange of ideas and thinking skills for the others. The teacher had a tremendous influence over the production of higher-level statements by modeling that level of thinking as she questioned the students. Through her practice of answering a question with a question, she gradually solicited more analytical thinking from her students.
Energy Technology Data Exchange (ETDEWEB)
Liu, Youshan, E-mail: ysliu@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); Teng, Jiwen, E-mail: jwteng@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); Xu, Tao, E-mail: xutao@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101 (China); Badal, José, E-mail: badal@unizar.es [Physics of the Earth, Sciences B, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain)
2017-05-01
The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate new cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant–Friedrichs–Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of computational
In-service teacher education: asking questions for higher order thinking in visual literacy
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Visvaganthie Moodley
2013-01-01
Full Text Available The kinds of questions teachers ask may thwart or promote learner high-order thinking; teachers themselves must have expertise in questioning skills to promote higher order cognition among learners. Drawing on experiential knowledge of assessment, and as an English-teaching professional development programme (PDP facilitator, I demonstrate that within the framework of a carefully structured subject-specific PDP, teachers can be taught how to enhance thinking skills in the English visual literacy (VL learning classroom. Guided by an earlier taxonomy of cognition, and using qualitative methodology, the paper analyses data obtained from: (i observation notes and examination equivalents of 40 teachers from various public schools in Gauteng who were engaged in the Advanced Certificate in Education (ACE, English specialization programme; and (ii a case study of three teachers by means of semi-structured interviews, and a study of their lesson plans and worksheets.The paper examines, specifically, teachers' choice of texts and questions asked, for English second-language learners for the teaching of VL. It concludes by suggesting that if teachers themselves are first engaged in the cognitive processes they wish learners to acquire, they are better positioned to promote higher order among their learners.
Molecular Behavior of DNA Origami in Higher-Order Self-Assembly
Energy Technology Data Exchange (ETDEWEB)
Li, Zhe [Arizona State Univ., Tempe, AZ (United States); Liu, Minghui [Arizona State Univ., Tempe, AZ (United States); Lei, Wang [Arizona State Univ., Tempe, AZ (United States); Shandong Univ., Jinan (China); Nangreave, Jeanette [Arizona State Univ., Tempe, AZ (United States); Yan, Hao [Arizona State Univ., Tempe, AZ (United States); Liu, Yan [Arizona State Univ., Tempe, AZ (United States)
2010-09-08
DNA-based self-assembly is a unique method for achieving higher-order molecular architectures made possible by the fact that DNA is a programmable information-coding polymer. In the past decade, two main types of DNA nanostructures have been developed: branch-shaped DNA tiles with small dimensions (commonly up to ~20 nm) and DNA origami tiles with larger dimensions (up to ~100 nm). Here we aimed to determine the important factors involved in the assembly of DNA origami superstructures. We constructed a new series of rectangular-shaped DNA origami tiles in which parallel DNA helices are arranged in a zigzag pattern when viewed along the DNA helical axis, a design conceived in order to relax an intrinsic global twist found in the original planar, rectangular origami tiles. Self-associating zigzag tiles were found to form linear arrays in both diagonal directions, while planar tiles showed significant growth in only one direction. Although the series of zigzag tiles were designed to promote two-dimensional array formation, one-dimensional linear arrays and tubular structures were observed instead. We discovered that the dimensional aspect ratio of the origami unit tiles and intertile connection design play important roles in determining the final products, as revealed by atomic force microscopy imaging. This study provides insight into the formation of higher-order structures from self-assembling DNA origami tiles, revealing their unique behavior in comparison with conventional DNA tiles having smaller dimensions.
On the Entropy Based Associative Memory Model with Higher-Order Correlations
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Masahiro Nakagawa
2010-01-01
Full Text Available In this paper, an entropy based associative memory model will be proposed and applied to memory retrievals with an orthogonal learning model so as to compare with the conventional model based on the quadratic Lyapunov functional to be minimized during the retrieval process. In the present approach, the updating dynamics will be constructed on the basis of the entropy minimization strategy which may be reduced asymptotically to the above-mentioned conventional dynamics as a special case ignoring the higher-order correlations. According to the introduction of the entropy functional, one may involve higer-order correlation effects between neurons in a self-contained manner without any heuristic coupling coefficients as in the conventional manner. In fact we shall show such higher order coupling tensors are to be uniquely determined in the framework of the entropy based approach. From numerical results, it will be found that the presently proposed novel approach realizes much larger memory capacity than that of the quadratic Lyapunov functional approach, e.g., associatron.
Measurement of mixed higher order flow harmonics in PbPb collisions
CMS Collaboration
2017-01-01
The mixed higher order flow harmonics and nonlinear response coefficients of charged particles are measured for the first time as a function of $p_{\\rm{T}}$ and centrality in PbPb collisions at $\\sqrt{s_{NN}} = 2.76~\\mathrm{TeV}$ and $5.02~\\mathrm{TeV}$ with the CMS detector. The results are obtained using the scalar product method, and cover a $p_{\\rm{T}}$ range from $0.3~\\mathrm{GeV}/c$ to $8.0~\\mathrm{GeV}/c$, pseudorapidity $|\\eta| < 2.4$, and a centrality range of $0-60\\%$. At $5.02~\\mathrm{TeV}$, results for mixed harmonics are compared to the matching higher order flow harmonics from two-particle correlations, which measure $v_n$ values with respect to the $n$-th order event plane. It is observed that the nonlinear response coefficients of the odd harmonics are larger than the even harmonics ones. The results are compared with hydrodynamic predictions with different shear viscosity to entropy density ratios and different initial conditions.
Higher-order Lorentz-invariance violation, quantum gravity and fine-tuning
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Carlos M. Reyes
2015-06-01
Full Text Available The issue of Lorentz fine-tuning in effective theories containing higher-order operators is studied. To this end, we focus on the Myers–Pospelov extension of QED with dimension-five operators in the photon sector and standard fermions. We compute the fermion self-energy at one-loop order considering its even and odd CPT contributions. In the even sector we find small radiative corrections to the usual parameters of QED which also turn to be finite. In the odd sector the axial operator is shown to contain unsuppressed effects of Lorentz violation leading to a possible fine-tuning. We use dimensional regularization to deal with the divergencies and a generic preferred four-vector. Taking the first steps in the renormalization procedure for Lorentz violating theories we arrive to acceptable small corrections allowing to set the bound ξ<6×10−3.
Analysis of EMG Signals in Aggressive and Normal Activities by Using Higher-Order Spectra
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Necmettin Sezgin
2012-01-01
Full Text Available The analysis and classification of electromyography (EMG signals are very important in order to detect some symptoms of diseases, prosthetic arm/leg control, and so on. In this study, an EMG signal was analyzed using bispectrum, which belongs to a family of higher-order spectra. An EMG signal is the electrical potential difference of muscle cells. The EMG signals used in the present study are aggressive or normal actions. The EMG dataset was obtained from the machine learning repository. First, the aggressive and normal EMG activities were analyzed using bispectrum and the quadratic phase coupling of each EMG episode was determined. Next, the features of the analyzed EMG signals were fed into learning machines to separate the aggressive and normal actions. The best classification result was 99.75%, which is sufficient to significantly classify the aggressive and normal actions.
Fundamental measure theory for smectic phases: scaling behavior and higher order terms.
Wittmann, René; Marechal, Matthieu; Mecke, Klaus
2014-08-14
The recent extension of Rosenfeld's fundamental measure theory to anisotropic hard particles predicts nematic order of rod-like particles. Our analytic study of different aligned shapes provides new insights into the structure of this density functional, which is basically founded on experience with hard spheres. We combine scaling arguments with dimensional crossover and motivate a modified expression, which enables an appropriate description of smectic layering. We calculate the nematic-smectic-A transition of monodisperse hard spherocylinders with and without orientational degrees of freedom and present the equation of state and phase diagram including these two liquid crystalline phases in good agreement with simulations. We also find improved results related to the isotropic-nematic interface. We discuss the quality of empirical corrections and the convergence towards an exact second virial coefficient, including higher order terms.
Yilmaz, Ferkan
2012-01-01
The higher-order statistics (HOS) of the channel capacity $\\mu_n=\\mathbb{E}[\\log^n(1+\\gamma_{end})]$, where $n\\in\\mathbb{N}$ denotes the order of the statistics, has received relatively little attention in the literature, due in part to the intractability of its analysis. In this letter, we propose a novel and unified analysis, which is based on the moment generating function (MGF) technique, to exactly compute the HOS of the channel capacity. More precisely, our mathematical formalism can be readily applied to maximal-ratio-combining (MRC) receivers operating in generalized fading environments. The mathematical formalism is illustrated by some numerical examples focussing on the correlated generalized fading environments.
A Formalization of Newman's and Yokouchi's Lemmas in a Higher-Order Language
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Andre Luiz Galdino
2008-12-01
Full Text Available This paper shows how a formalization for the theory of Abstract Reduction Systems (ARSs in which noetherianity was specified by the notion of well-foundness over binary relations is used in order to prove results such as the well-known Newman's and Yokouchi's Lemmas. The former is known as the diamond lemma and the latter states a property of commutation between ARSs. The theory ars was specified in the Prototype Verification System (PVS for which to the best of our knowledge there was no available theory for dealing with rewriting techniques in general before this development. In addition to proof techniques available in the higher-order specification language of PVS, the verification of these lemmas implies an elaborated use of natural and noetherian induction.
Reproduction of nearby sound sources using higher-order ambisonics with practical loudspeaker arrays
DEFF Research Database (Denmark)
Favrot, Sylvain Emmanuel; Buchholz, Jörg
2012-01-01
In order to reproduce nearby sound sources with distant loudspeakers to a single listener, the near field compensated (NFC) method for higher-order Ambisonics (HOA) has been previously proposed. In practical realization, this method requires the use of regularization functions. This study analyzes...... the impact of two existing and a new proposed regularization function on the reproduced sound fields and on the main auditory cue for nearby sound sources outside the median plane, i.e, low-frequencies interaural level differences (ILDs). The proposed regularization function led to a better reproduction...... of point source sound fields compared to existing regularization functions for NFC-HOA. Measurements in realistic playback environments showed that, for very close sources, significant ILDs for frequencies above about 250 Hz can be reproduced with NFC-HOA and the proposed regularization function whereas...
Double Quarter Wave Crab Cavity Field Profile Analysis and Higher Order Mode Characterization
Energy Technology Data Exchange (ETDEWEB)
Marques, Carlos [Brookhaven National Lab. (BNL), Upton, NY (United States). Accelerator R and D Div.; Stony Brook Univ., NY (United States). Physics and Astronomy Dept.; Xiao, B. P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Accelerator R and D Div.; Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Accelerator R and D Div.; Stony Brook Univ., NY (United States). Physics and Astronomy Dept.
2014-06-01
The Large Hadron Collider (LHC) is underway for a major upgrade to increase its luminosity by an order of magnitude beyond its original design specifications. This novel machine configuration known as the High Luminosity LHC (HL-LHC) will rely on various innovative technologies including very compact and ultra-precise superconducting crab cavities for beam rotation. A double quarter wave crab cavity (DQWCC) has been designed at Brookhaven National Laboratory for the HL-LHC. This cavity as well as the structural support components were fabricated and assembled at Niowave. The field profile of the crabbing mode for the DQWCC was investigated using a phase shift bead pulling technique and compared with simulated results to ensure proper operation or discover discrepancies from modeled results and/or variation in fabrication tolerances. Higher-Order Mode (HOM) characterization was also performed and correlated with simulations.
Directory of Open Access Journals (Sweden)
Giovanni A. Salum
2016-03-01
Full Text Available Objective To investigate the validity and reliability of a multi-informant approach to measuring child maltreatment (CM comprising seven questions assessing CM administered to children and their parents in a large community sample. Methods Our sample comprised 2,512 children aged 6 to 12 years and their parents. Child maltreatment (CM was assessed with three questions answered by the children and four answered by their parents, covering physical abuse, physical neglect, emotional abuse and sexual abuse. Confirmatory factor analysis was used to compare the fit indices of different models. Convergent and divergent validity were tested using parent-report and teacher-report scores on the Strengths and Difficulties Questionnaire. Discriminant validity was investigated using the Development and Well-Being Assessment to divide subjects into five diagnostic groups: typically developing controls (n = 1,880, fear disorders (n = 108, distress disorders (n = 76, attention deficit hyperactivity disorder (n = 143 and oppositional defiant disorder/conduct disorder (n = 56. Results A higher-order model with one higher-order factor (child maltreatment encompassing two lower-order factors (child report and parent report exhibited the best fit to the data and this model's reliability results were acceptable. As expected, child maltreatment was positively associated with measures of psychopathology and negatively associated with prosocial measures. All diagnostic category groups had higher levels of overall child maltreatment than typically developing children. Conclusions We found evidence for the validity and reliability of this brief measure of child maltreatment using data from a large survey combining information from parents and their children.
Saidi, Lotfi; Ben Ali, Jaouher; Fnaiech, Farhat
2015-01-01
Condition monitoring and fault diagnosis of rolling element bearings timely and accurately are very important to ensure the reliability of rotating machinery. This paper presents a novel pattern classification approach for bearings diagnostics, which combines the higher order spectra analysis features and support vector machine classifier. The use of non-linear features motivated by the higher order spectra has been reported to be a promising approach to analyze the non-linear and non-Gaussian characteristics of the mechanical vibration signals. The vibration bi-spectrum (third order spectrum) patterns are extracted as the feature vectors presenting different bearing faults. The extracted bi-spectrum features are subjected to principal component analysis for dimensionality reduction. These principal components were fed to support vector machine to distinguish four kinds of bearing faults covering different levels of severity for each fault type, which were measured in the experimental test bench running under different working conditions. In order to find the optimal parameters for the multi-class support vector machine model, a grid-search method in combination with 10-fold cross-validation has been used. Based on the correct classification of bearing patterns in the test set, in each fold the performance measures are computed. The average of these performance measures is computed to report the overall performance of the support vector machine classifier. In addition, in fault detection problems, the performance of a detection algorithm usually depends on the trade-off between robustness and sensitivity. The sensitivity and robustness of the proposed method are explored by running a series of experiments. A receiver operating characteristic (ROC) curve made the results more convincing. The results indicated that the proposed method can reliably identify different fault patterns of rolling element bearings based on vibration signals. Copyright © 2014 ISA
Soliton dynamics for trapped Bose-Einstein condensate with higher-order interaction
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Ying Wang
2017-08-01
Full Text Available We model the three-dimensional (3D trapped Bose-Einstein condensate with the Gross-Pitaevskii equation (GPE incorporating higher-order nonlinear interaction effects. Based on the F-expansion method and self-similar approach, we analytically derive the exact soliton solutions of the 3D GPE, identifying the oscillatory mode under certain experimental settings. The oscillatory kinetic parameter values we obtained coincide very well with those reported in previous work, which is based on the variational approach, showing the applicability of the theoretical treatment presented in this work.
Exploring evidence of higher order thinking skills in the writing of first year undergraduates
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Lynette Faragher
2014-08-01
Full Text Available Research indicates that concern is often expressed about the language and discourse skills new students bring with them when they first enrol at university, which leads to assumptions being made about their academic abilities. In this paper, an argument is developed through detailed analysis of student writing, that many new first year students have nascent Higher Order Thinking Skills and the potential to be successful in their studies. The work of Robert Marzano and his associates (Marzano, 2001; Marzano & Kendall, 2007, 2008 is applied to student writing.
Higher Order Mode (HOM) Impedance and Damping Study for the LHC Capture Cavity
Linnecar, Trevor Paul R; Tückmantel, Joachim; CERN. Geneva. SPS and LHC Division
2001-01-01
To investigate the higher order mode, HOM, damping in the LHC 200MHz ACN cavity when using four HOM couplers, simulations have been done by both 3-D frequency domain and time domain methods. These simulations have previously been used in other studies of HOM damped cavities and shown to be effective by comparing measurement and simulation results[1] [2]. Using these methods the impedance spectrum of the HOM modes in the cavity before and after damping has been obtained. From this, detailed information about the HOM coupler's contribution to HOM damping can be obtained. The distribution and magnitude of some potentially dangerous HOM modes in the ACN cavity have been found.
Wake and higher order mode computations for the CMS experimental chamber at the LHC
Wanzenberg, R
2010-01-01
Wakefields and trapped Higher Order Modes (HOMs) in the CMS experimental chamber at the LHC are investigated using a geometrical model which closely reflects the presently installed vacuum chamber. The basic rf-parameters of the HOMs including the frequency, loss parameter, and the Q-value are provided. To cover also transient effects the short range wakefields and the total loss parameter has been calculated, too. Most numerical calculations are performed with the computer code MAFIA. The calculations of the Modes are complemented with an analysis of the multi-bunch instabilities due to the longitudinal and dipole modes in the CMS vacuum chamber.
Higher-Order Structure in Bacterial VapBC Toxin-Antitoxin Complexes
DEFF Research Database (Denmark)
Bendtsen, Kirstine L; Brodersen, Ditlev E
2017-01-01
Toxin-antitoxin systems are widespread in the bacterial kingdom, including in pathogenic species, where they allow rapid adaptation to changing environmental conditions through selective inhibition of key cellular processes, such as DNA replication or protein translation. Under normal growth...... that allow auto-regulation of transcription by direct binding to promoter DNA. In this chapter, we review our current understanding of the structural characteristics of type II toxin-antitoxin complexes in bacterial cells, with a special emphasis on the staggering variety of higher-order architecture...
Higher Order Relations for ADE-Type Generalized q-Onsager Algebras
Baseilhac, Pascal; Vu, Thi Thao
2015-09-01
Let be the fundamental generators of the generalized q-Onsager algebra introduced in Baseilhac and Belliard (Lett Math Phys 93:213-228, 2010), where is a simply laced affine Lie algebra. New relations between certain monomials of the fundamental generators—indexed by the integer —are conjectured. These relations can be seen as deformed analogs of Lusztig's rth higher order q-Serre relations associated with , which are recovered as special cases. The relations are proven for . For r generic, several supporting evidences are presented.
A new approach to the higher order superintegrability of the Tremblay-Turbiner-Winternitz system
Rañada, Manuel F.
2012-11-01
The higher order superintegrability of systems separable in polar coordinates is studied using an approach that was previously applied for the study of the superintegrability of a generalized Smorodinsky-Winternitz system. The idea is that the additional constant of motion can be factorized as the product of powers of two particular rather simple complex functions (here denoted by M and N). This technique leads to a proof of the superintegrability of the Tremblay-Turbiner-Winternitz system and to the explicit expression of the constants of motion. A second family (related with the first one) of superintegrable systems is also studied.
Effects of polyamines on higher-order folding of in situ chromatin.
Vergani, L; Mascetti, G; Nicolini, C
1998-11-01
Modifications of the higher-order chromatin structure induced by polyamines have been quantitatively investigated in situ through a non-invasive biophysical approach using Differential Scanning Calorimetry and Quantitative Fluorescence Microscopy. Calorimetric and intensitometric profiles have been acquired for samples of native thymocytes, alternatively suspended in buffers, with or without natural polyamines (spermine and spermidine). The results here reported show that the structure and distribution of nuclear chromatin in situ considerably change upon the ionic composition of the environment. A quantitative analysis of this data and a comparison with previous results obtained from isolated chromatin fibers was carried out. Finally, an inverse relationship between chromatin condensation and nuclear volume was observed.
Higher order Painleve equations and their symmetries via reductions of a class of integrable models
Energy Technology Data Exchange (ETDEWEB)
Aratyn, H [Department of Physics, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607-7059 (United States); Gomes, J F; Zimerman, A H, E-mail: jfg@ift.unesp.br [Instituto de Fisica Teorica-UNESP, Rua Dr Bento Teobaldo Ferraz 271, Bloco II, 01140-070 Sao Paulo (Brazil)
2011-06-10
Higher order Painleve equations and their symmetry transformations belonging to extended affine Weyl groups A{sup (1)}{sub n} are obtained through a self-similarity limit of a class of pseudo-differential Lax hierarchies with symmetry inherited from the underlying generalized Volterra lattice structure. In particular, an explicit example of the Painleve V equation and its Baecklund symmetry is obtained through a self-similarity limit of a generalized KdV hierarchy from Aratyn et al (1995 Int. J. Mod. Phys. A 10 2537).
Simulation of Airborne Antenna Array Layout Problems Using Parallel Higher-Order MoM
Directory of Open Access Journals (Sweden)
Zhongchao Lin
2014-01-01
Full Text Available The parallel higher-order Method of Moments based on message passing interface (MPI has been successfully used to analyze the changes in radiation patterns of a microstrip patch array antenna mounted on different positions of an airplane. The block-partitioned scheme for the large dense MoM matrix and a block-cyclic matrix distribution scheme are designed to achieve excellent load balance and high parallel efficiency. Numerical results demonstrate that the rigorous parallel Method of Moments can efficiently and accurately solve large complex electromagnetic problems with composite structures.
On the formulations of higher-order strain gradient crystal plasticity models
DEFF Research Database (Denmark)
Kuroda, M.; Tvergaard, Viggo
2008-01-01
Recently, several higher-order extensions to the crystal plasticity theory have been proposed to incorporate effects of material length scales that were missing links in the conventional continuum mechanics. The extended theories are classified into work-conjugate and non-work-conjugate types...... quantities do not appear explicitly. Instead, rates of crystallographic slip are influenced by back stresses that arise in response to spatial gradients of the geometrically necessary dislocation densities. The work-conjugate type and the non-work-conjugate type of theories have different theoretical...
Elishakoff, Isaac; Librescu, Liviu; Cederbaum, Gabriel
1990-01-01
Higher order shear deformation theory is utilized to study he weakly stationary and nonstationary random vibrations of cross-ply laminated plates. Normal mode method, in conjunction with the biorthogonality condition, for the nonsymmetric differential equations is applied. Detailed derivation is given for the governing equations, biorthogonality condition, the generalized mass and the generalized forces. Results are listed for a plate which is simply supported at all the edges, and subjected to a point load which is either timewise stationary or nonstationary random process.
Dynamic analysis of laminated plates using a higher-order theory
Reddy, J. N.; Phan, N. D.
1984-01-01
This paper deals with the dynamic analog of the higher-order shear deformation plate theory developed by the senior author. The theory is based on a displacement field in which the inplane displacements are expanded as cubic functions of the thicknes coordinate and the transverse deflection is assumed to be constant through the thickness. The additional dependent unkowns introduced with the quadratic and cubic terms of the thickness coordinate are eliminated by requiring the transverse shear stresses to vanish on the bounding planes of the plate. The theory accounts for the parabolic distribution of the transverse shear stresses, and hence no shear correction coefficients are required.
Analysis of laminated composite plates using a higher-order shear deformation theory
Phan, N. D.; Reddy, J. N.
1985-01-01
A higher-order deformation theory is used to analyse laminated anisotropic composite plates for deflections, stresses, natural frequencies and buckling loads. The theory accounts for parabolic distribution of the transverse shear stresses, and requires no shear correction coefficients. A displacement finite element model of the theory is developed, and applications of the element to bending, vibration and stability of laminated plates are discussed. The present solutions are compared with those obtained using the classical plate theory and the three-dimensional elasticity theory.
Random walker in temporally deforming higher-order potential forces observed in a financial crisis.
Watanabe, Kota; Takayasu, Hideki; Takayasu, Misako
2009-11-01
Basic peculiarities of market price fluctuations are known to be well described by a recently developed random-walk model in a temporally deforming quadratic potential force whose center is given by a moving average of past price traces [M. Takayasu, T. Mizuno, and H. Takayasu, Physica A 370, 91 (2006)]. By analyzing high-frequency financial time series of exceptional events, such as bubbles and crashes, we confirm the appearance of higher-order potential force in the markets. We show statistical significance of its existence by applying the information criterion. This time series analysis is expected to be applied widely for detecting a nonstationary symptom in random phenomena.
On the regularity of mild solutions to complete higher order differential equations on Banach spaces
Directory of Open Access Journals (Sweden)
Nezam Iraniparast
2015-09-01
Full Text Available For the complete higher order differential equation u(n(t=Σk=0n-1Aku(k(t+f(t, t∈ R (* on a Banach space E, we give a new definition of mild solutions of (*. We then characterize the regular admissibility of a translation invariant subspace al M of BUC(R, E with respect to (* in terms of solvability of the operator equation Σj=0n-1AjXal Dj-Xal Dn = C. As application, almost periodicity of mild solutions of (* is proved.
Observation of higher-order snake resonances in polarized proton acceleration in RHIC.
Ranjbar, V H; Lee, S Y; Huang, H; Luccio, A U; MacKay, W W; Ptitsyn, V; Roser, T; Tepikian, S
2003-07-18
Higher-order and coupled snake resonances were observed during the 2002 polarized proton run in RHIC. Strong depolarization was observed when the fractional part of the vertical betatron tune approached 1/4, and when the fractional part of the horizontal tune approached 3/14. Because of the closed orbit error, each snake resonance splits into two. From the width of the observed snake resonances, we can derive the strength of the imperfection spin resonance. Our results appear consistent with the measured closed orbit error.
Effect of impedance and higher order chromaticity on the measurement of linear chromaticity
Energy Technology Data Exchange (ETDEWEB)
Ranjbar, V.H.; /Tech-X, Boulder; Tan, C.Y.; /Fermilab
2011-08-01
The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta with respect to the 'on momentum' particle ({Delta}p/p). Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of {Delta}p/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used to support the theory.
Polynomial Expansions for Solutions of Higher-Order Bessel Heat Equation in Quantum Calculus
Ben Hammouda, M.S.; Nemri, Akram
2007-01-01
Mathematics Subject Class.: 33C10,33D60,26D15,33D05,33D15,33D90 In this paper we give the q-analogue of the higher-order Bessel operators studied by I. Dimovski [3],[4], I. Dimovski and V. Kiryakova [5],[6], M. I. Klyuchantsev [17], V. Kiryakova [15], [16], A. Fitouhi, N. H. Mahmoud and S. A. Ould Ahmed Mahmoud [8], and recently by many other authors. Our objective is twofold. First, using the q-Jackson integral and the q-derivative, we aim at establishing some properties of...
Higher-order brain function analysis by trans-cranial dynamic near-infrared spectroscopy imaging
Koizumi, Hideaki; Yamashita, Yuichi; Maki, Atsushi; Yamamoto, Tsuyoshi; Ito, Yoshitoshi; Itagaki, H.; Kennan, R.
1999-10-01
Near-infrared spectroscopy is discussed from the viewpoint of human higher-order brain function analysis. Pioneering work in this field is reviewed; then we describe our concept of noninvasive trans-cranial dynamic optical topography and its instrumentation. Also, the validity of its functional images is assessed from both physical and physiological viewpoints. After conforming the validity of this method, we have applied it to a wide variety of fields such as clinical medicine, cognitive science, and linguistics in collaboration with researchers at several other institutes. Further application possibilities and the future of trans- cranial dynamic optical topography are also discussed.
Adaptive grouping for the higher-order multilevel fast multipole method
DEFF Research Database (Denmark)
Borries, Oscar Peter; Jørgensen, Erik; Meincke, Peter
2014-01-01
functions. Results from both a uniformly and nonuniformly meshed scatterer are presented, showing how the technique is worthwhile even for regular meshes, and demonstrating that there is no loss of accuracy in spite of the large reduction in memory requirements and the relatively low computational cost.......An alternative parameter-free adaptive approach for the grouping of the basis function patterns in the multilevel fast multipole method is presented, yielding significant memory savings compared to the traditional Octree grouping for most discretizations, particularly when using higher-order basis...
Nonlinear optics in the LP(02) higher-order mode of a fiber.
Chen, Y; Chen, Z; Wadsworth, W J; Birks, T A
2013-07-29
The distinct disperion properties of higher-order modes in optical fibers permit the nonlinear generation of radiation deeper into the ultraviolet than is possible with the fundamental mode. This is exploited using adiabatic, broadband mode convertors to couple light efficiently from an input fundamental mode and also to return the generated light to an output fundamental mode over a broad spectral range. For example, we generate visible and UV supercontinuum light in the LP(02) mode of a photonic crystal fiber from sub-ns pulses with a wavelength of 532 nm.
A Simple Model of Separation Logic for Higher-order Store
DEFF Research Database (Denmark)
Birkedal, Lars; Reus, Bernhard; Schwinghammer, Jan
2008-01-01
Separation logic is a Hoare-style logic for reasoning about pointer-manipulating programs. Its core ideas have recently been extended from low-level to richer, high-level languages. In this paper we develop a new semantics of the logic for a programming language where code can be stored (i.......e., with higher-order store). The main improvement on previous work is the simplicity of the model. As a consequence, several restrictions imposed by the semantics are removed, leading to a considerably more natural assertion language with a powerful specification logic....
Davidson, Judy E
2009-03-01
The purpose of this article is to provide examples of learning activities to be used as formative (interim) evaluation of an in-hospital orientation or cross-training program. Examples are provided in the form of vignettes that have been derived from strategies described in the literature as classroom assessment techniques. Although these classroom assessment techniques were originally designed for classroom experiences, they are proposed as methods for preceptors to stimulate the development of higher-order thinking such as synthesizing information, solving problems, and learning how to learn.
Higher order modes HOMs in coupled cavities of the FLASH module ACC39
Shinton, I R R; Li, Z; Zhang, P
2011-01-01
We analyse the higher order modes (HOM’s) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.
Random walker in temporally deforming higher-order potential forces observed in a financial crisis
Watanabe, Kota; Takayasu, Hideki; Takayasu, Misako
2009-11-01
Basic peculiarities of market price fluctuations are known to be well described by a recently developed random-walk model in a temporally deforming quadratic potential force whose center is given by a moving average of past price traces [M. Takayasu, T. Mizuno, and H. Takayasu, Physica A 370, 91 (2006)]. By analyzing high-frequency financial time series of exceptional events, such as bubbles and crashes, we confirm the appearance of higher-order potential force in the markets. We show statistical significance of its existence by applying the information criterion. This time series analysis is expected to be applied widely for detecting a nonstationary symptom in random phenomena.
Analysis of four aberrometers for evaluating lower and higher order aberrations.
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Fabiano Cade
Full Text Available PURPOSE: To compare the measurements of lower and higher order aberrations (HOA of 4 commonly used aberrometers. SETTING: Massachusetts Eye & Ear Infirmary, Boston, USA. DESIGN: Prospective, cross-sectional study, in a controlled, single-blinded fashion. METHODS: Multiple readings were obtained in 42 eyes of 21 healthy volunteers, at a single visit, with each of the following aberrometers: Alcon LADARWave®, Visx WaveScan®, B & L Zywave®, and Wavelight Allegro Analyzer®. Results were compared and analyzed in regards to the lower and HOA, to the different wavefront sensing devices and software, Tscherning and Hartmann-Shack and between the Fourier and Zernike algorithms. Statistical analysis included Bland-Altman plots, Intraclass Correlation Coefficient (ICC, multiple comparison tests with Analysis of Variance and Kruskal-Wallis. Significant level was set to p<0.05 and alpha level correction was adjusted under the Bonferroni criteria. RESULTS: Most measurements of all 4 aberrometers were comparable. However, statistically significant differences were found between the aberrometers in total HOA (tHOA, spherical aberration (SA, horizontal coma and astigmatism (2,2. LADARwave and Wavescan showed significant differences in tHOA (P<0.001, ICC = 0.549, LoA = 0.19±0.5 and in SA (P<0.001, ICC = 0.733, LoA = 0.16±0.37. Wavescan showed a significant difference compared to Zywave (p<0.001, ICC = 0.920, LoA = 0.09±0.13 in SA. Comparisons between Allegro Analyzer and Zywave demonstrated significant differences in both Horizontal Coma (3,1 (p<0.001, ICC = -0.207, LoA = -0.15±0.48 and Astigmatism (2,2 (P = 0.003, ICC = -0.965, LoA = 0.2±2.5. Allegro Analyzer also differed from Wavescan in Horizontal Coma (3,1 (P<0.001, ICC = 0.725, LoA = -0.07±0.25. CONCLUSIONS: Although some measurements were comparable predominately in the lower order aberrations, significant differences were found in the tHOA, SA, horizontal coma and astigmatism. Our analysis
Practical microstructured and plasmonic terahertz waveguides
Markov, Andrey
The terahertz frequency range, with frequencies lying between 100 GHz and 10 THz, has strong potential for various technological and scientific applications such as sensing, imaging, communications, and spectroscopy. Most terahertz (THz) sources are immobile and THz systems use free-space propagation in dry air where losses are minimal. Designing efficient THz waveguides for flexible delivery of broadband THz radiation is an important step towards practical applications of terahertz techniques. THz waveguides can be very useful on the system integration level when used for connection of the diverse THz point devices, such as sources, filters, sensor cells, detectors, etc. The most straightforward application of waveguides is to deliver electromagnetic waves from the source to the point of detection. Cumbersome free-space optics can be replaced by waveguides operating in the THz range, which could lead to the development of compact THz time domain spectroscopy systems. Other promising applications of THz waveguides are in sensing and imaging. THz waveguides have also been shown to operate in subwavelength regimes, offering mode confinement in waveguide structures with a size smaller than the diffraction limit, and thus, surpassing the resolution of free-space THz imaging systems. In order to design efficient terahertz waveguides, the frequency dependent loss and dispersion of the waveguide must be minimized. A possible solution would be to increase the fraction of mode power propagating through air. In this thesis, the usage of planar porous air/dielectric waveguides and metal wire/dielectric hybrid terahertz fibers will be discussed. First, I present a novel design of a planar porous low-loss waveguide, describe its fabrication, and characterize it in view of its potential applications as a low-loss waveguide and sensor in the THz spectral range. The waveguide structure features a periodic sequence of layers of thin (25-50 mum) polyethylene film that are separated
Energy Technology Data Exchange (ETDEWEB)
Candel, A.; Kabel, A.; Lee, L.; Li, Z.; Limborg, C.; Ng, C.; Prudencio, E.; Schussman, G.; Uplenchwar, R.; Ko, K.; /SLAC
2009-06-19
Over the past years, SLAC's Advanced Computations Department (ACD), under SciDAC sponsorship, has developed a suite of 3D (2D) parallel higher-order finite element (FE) codes, T3P (T2P) and Pic3P (Pic2P), aimed at accurate, large-scale simulation of wakefields and particle-field interactions in radio-frequency (RF) cavities of complex shape. The codes are built on the FE infrastructure that supports SLAC's frequency domain codes, Omega3P and S3P, to utilize conformal tetrahedral (triangular)meshes, higher-order basis functions and quadratic geometry approximation. For time integration, they adopt an unconditionally stable implicit scheme. Pic3P (Pic2P) extends T3P (T2P) to treat charged-particle dynamics self-consistently using the PIC (particle-in-cell) approach, the first such implementation on a conformal, unstructured grid using Whitney basis functions. Examples from applications to the International Linear Collider (ILC), Positron Electron Project-II (PEP-II), Linac Coherent Light Source (LCLS) and other accelerators will be presented to compare the accuracy and computational efficiency of these codes versus their counterparts using structured grids.
Penner, Jacob; Osuch, Elizabeth A; Schaefer, Betsy; Théberge, Jean; Neufeld, Richard W J; Menon, Ravi S; Rajakumar, Nagalingam; Bourne, James A; Williamson, Peter C
2017-12-08
The pulvinar and the mediodorsal (MDN) nuclei of the thalamus are higher order nuclei which have been implicated in directed effort and corollary discharge systems. We used seed-based resting fMRI to examine functional connectivity to bilateral pulvinar and MDN in 24 schizophrenic patients (SZ), 24 major depressive disorder patients (MDD), and 24 age-matched healthy controls. SZ had less connectivity than controls between the left pulvinar and precuneus, left ventral-lateral prefrontal cortex (vlPFC), and superior and medial-frontal regions, between the right pulvinar and right frontal pole, and greater connectivity between the right MDN and left dorsolateral prefrontal cortex (dlPFC). SZ had less connectivity than MDD between the left pulvinar and ventral anterior cingulate (vACC), left vlPFC, anterior insula, posterior cingulate cortex (PCC), and right hippocampus, between the right pulvinar and right PCC, and between the right MDN and right dorsal anterior cingulate (dACC). This is the first study to measure the functional connectivity to the higher order nuclei of the thalamus in both SZ and MDD. We observed less connectivity in SZ than MDD between pulvinar and emotional encoding regions, a directed effort region, and a region involved in representation and salience, and between MDN and a directed effort region. Copyright © 2017 Elsevier B.V. All rights reserved.
Model-based iterative reconstruction using higher-order regularization of dynamic synchrotron data
Kazantsev, Daniil; Guo, Enyu; Phillion, A. B.; Withers, Philip J.; Lee, Peter D.
2017-09-01
We present a novel iterative reconstruction method applied to in situ x-ray synchrotron tomographic data of dendrite formation during the solidification of magnesium alloy. Frequently, fast dynamic imaging projection data are undersampled, noisy, of poor contrast and can contain various acquisition artifacts. Direct reconstruction methods are not suitable and iterative reconstruction techniques must be adapted to the existing data features. Normally, an accurate modelling of the objective function can guarantee a better reconstruction. In this work, we design a special cost function where the data fidelity term is based on the Group-Huber functional to minimize ring artifacts and the regularization term is a higher-order variational penalty. We show that the total variation penalty is unsuitable for some cases and higher-order regularization functionals can ensure a better fit to the expected properties of the data. Additionally, we highlight the importance of 3D regularization over 2D for the problematic data. The proposed method shows a promising performance dealing with angular undersampled noisy dynamic data with ring artifacts.
Mrochen, M; Kaemmerer, M; Mierdel, P; Seiler, T
2001-03-01
To study the clinical and theoretical effects of subclinical decentrations on the optical performance of the eye after photorefractive laser surgery. Department of Ophthalmology, University of Dresden, Dresden, Germany. Ocular aberrations were determined before and 1 month after uneventful photorefractive keratectomy (PRK) with the Multiscan laser (Schwind) in 10 eyes of 8 patients. The corrections ranged from -2.5 to -6.0 diopters, and ablation zones of 6.0 mm and larger were used. The measured wavefront errors were compared to numerical simulations using the individually determined decentrations and currently used ablation profiles. The PRK-induced aberrations were significantly greater than the preoperative aberrations. The numerically calculated increase in the higher-order optical aberrations correlated with the clinical results, demonstrating a major increase in coma- and spherical-like aberrations. Subclinical decentration (less than 1.0 mm) was found to be a major factor in increased coma-like and spherical-like aberrations after corneal laser surgery. To minimize higher-order optical errors, special efforts to center the ablation zone are necessary; for example, by eye-tracking systems that consider the visual axis.
A Concatenation Scheme for the Computation of Beam Excited Higher Order Mode Port Signals
Flisgen, T; van Rienen, U
2013-01-01
Ongoing studies investigate in how far higher order mode (HOM) port signals of superconducting RF cavities can be used for machine and beam diagnostics. Apart from experiments e.g. at the FLASH facility at DESY in Hamburg, numerical modelling is needed for the prediction of HOM coupler signals. For this purpose, the RF properties of the entire accelerating module have to be taken into account, since higher order modes can propagate along the cavity chain. A discretization of the full chain, followed by a wake field simulation is only feasible with powerful and expensive cluster computers. Instead, an element-wise wake field simulation of subsections of the chain, followed by a suitable concatenation scheme can be performed on standard hardware assuming the beam to be sufficiently stiff. In this paper a concatenation scheme for the computation of beam excited HOM port signals is derived as a generalization of the Coupled S-Parameter scheme CSC. Furthermore, the validity of the method is shown for a sample stru...
Higher order thinking skills competencies required by outcomes-based education from learners
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MM Chabeli
2006-09-01
Full Text Available Outcomes-Based Education (OBE brought about a significant paradigm shift in the education and training of learners in South Africa. OBE requires a shift from focusing on the teacher input (instruction offerings or syllabuses expressed in terms of content, to focusing on learner outcomes. OBE is moving away from ‘transmission’ models to constructivistic, learner-centered models that put emphasis on learning as an active process (Nieburh, 1996:30. Teachers act as facilitators and mediators of learning (Norms and Standards, Government Gazette vol 415, no 20844 of 2000. Facilitators are responsible to create the environment that is conducive for learners to construct their own knowledge, skills and values through interaction (Peters, 2000. The first critical cross-field outcome accepted by the South African Qualification Framework (SAQA is that learners should be able to identify and solve problems by using critical and creative thinking skills. This paper seeks to explore some higher order thinking skills competencies required by OBE from learners such as critical thinking, reflective thinking, creative thinking, dialogic / dialectic thinking, decision making, problem solving and emotional intelligence and their implications in facilitating teaching and learning from the theoretical perspective. The philosophical underpinning of these higher order thinking skills is described to give direction to the study. It is recommended that a study focusing on the assessment of these intellectual concepts be made. The study may be qualitative, quantitative or mixed methods in nature (Creswell 2005.
Higher order thinking skills competencies required by outcomes-based education from learners.
Chabeli, M M
2006-08-01
Outcomes-Based Education (OBE) brought about a significant paradigm shift in the education and training of learners in South Africa. OBE requires a shift from focusing on the teacher input (instruction offerings or syllabuses expressed in terms of content), to focusing on learner outcomes. OBE is moving away from 'transmission' models to constructivistic, learner-centered models that put emphasis on learning as an active process (Nieburh, 1996:30). Teachers act as facilitators and mediators of learning (Norms and Standards, Government Gazette vol 415, no 20844 of 2000). Facilitators are responsible to create the environment that is conducive for learners to construct their own knowledge, skills and values through interaction (Peters, 2000). The first critical cross-field outcome accepted by the South African Qualification Framework (SAQA) is that learners should be able to identify and solve problems by using critical and creative thinking skills. This paper seeks to explore some higher order thinking skills competencies required by OBE from learners such as critical thinking, reflective thinking, creative thinking, dialogic / dialectic thinking, decision making, problem solving and emotional intelligence and their implications in facilitating teaching and learning from the theoretical perspective. The philosophical underpinning of these higher order thinking skills is described to give direction to the study. It is recommended that a study focusing on the assessment of these intellectual concepts be made. The study may be qualitative, quantitative or mixed methods in nature (Creswell 2005).
ISWI regulates higher-order chromatin structure and histone H1 assembly in vivo.
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Davide F V Corona
2007-09-01
Full Text Available Imitation SWI (ISWI and other ATP-dependent chromatin-remodeling factors play key roles in transcription and other processes by altering the structure and positioning of nucleosomes. Recent studies have also implicated ISWI in the regulation of higher-order chromatin structure, but its role in this process remains poorly understood. To clarify the role of ISWI in vivo, we examined defects in chromosome structure and gene expression resulting from the loss of Iswi function in Drosophila. Consistent with a broad role in transcriptional regulation, the expression of a large number of genes is altered in Iswi mutant larvae. The expression of a dominant-negative form of ISWI leads to dramatic alterations in higher-order chromatin structure, including the apparent decondensation of both mitotic and polytene chromosomes. The loss of ISWI function does not cause obvious defects in nucleosome assembly, but results in a significant reduction in the level of histone H1 associated with chromatin in vivo. These findings suggest that ISWI plays a global role in chromatin compaction in vivo by promoting the association of the linker histone H1 with chromatin.
Jaber, Nizar
2016-01-06
© 2016 IOP Publishing Ltd. In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped-clamped microbeam resonators. The concept is based on using partial electrodes with shapes that induce strong excitation of the mode of interest. The devices are fabricated using polyimide as a structural layer coated with nickel from the top and chrome and gold layers from the bottom. Experimentally, frequency sweeps with different electro-dynamical loading conditions are shown to demonstrate the excitation of the higher order modes of vibration. Using a half electrode, the second mode is excited with high amplitude of vibration compared with almost zero response using the full electrode. Also, using a two-third electrode configuration is shown to amplify the third mode resonance amplitude compared with the full electrode under the same electrical loading conditions. An analytical model is developed based on the Euler-Bernollui beam model and the Galerkin method to simulate the device response. Good agreement between the simulation results and the experimental data is reported.
A novel nature inspired firefly algorithm with higher order neural network: Performance analysis
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Janmenjoy Nayak
2016-03-01
Full Text Available The applications of both Feed Forward Neural network and Multilayer perceptron are very diverse and saturated. But the linear threshold unit of feed forward networks causes fast learning with limited capabilities, while due to multilayering, the back propagation of errors exhibits slow training speed in MLP. So, a higher order network can be constructed by correlating between the input variables to perform nonlinear mapping using the single layer of input units for overcoming the above drawbacks. In this paper, a Firefly based higher order neural network has been proposed for data classification for maintaining fast learning and avoids the exponential increase of processing units. A vast literature survey has been conducted to review the state of the art of the previous developed models. The performance of the proposed method has been tested with various benchmark datasets from UCI machine learning repository and compared with the performance of other established models. Experimental results imply that the proposed method is fast, steady, reliable and provides better classification accuracy than others.
Higher-order semantic processing in formal thought disorder in schizophrenia.
Dwyer, Karen; David, Anthony; McCarthy, Rosaleen; McKenna, Peter; Peters, Emmanuelle
2014-05-15
Higher-order semantic impairments and lack of sensitivity to linguistic context have both been implicated in formal thought disorder (FTD) in schizophrenia. Most investigations have focused on comprehension. We investigated the processing of higher-order semantic relations and the role of emotional arousal in FTD patients' linguistic comprehension and production. We compared FTD schizophrenia patients (n=14) with non-FTD schizophrenia patients (n=18) and healthy controls (n=15) on sense-judgment and repetition tasks, in emotionally negative and neutral conditions. We predicted that the FTD group would display poor sensitivity compared to the other two groups in comprehension and production, and that this would be exacerbated by sentence complexity and negative emotional arousal. The emotional manipulation was not robustly successful, and did not affect task performance in the patient groups. FTD patients made significantly more errors on sense-judgments and repetition than the other two groups. Complexity affected all groups to a similar extent in sense-judgments, but affected FTD patients disproportionately in the repetition task. These results support the view that a lack of sensitivity to context underlies FTD in comprehension and production stages of processing. Patients fail to utilise linguistic context to integrate lexical forms into a global whole and guide their access to lexical targets. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Jinpil Tak
2015-01-01
Full Text Available A stepped cylindrical antenna with a higher-order mode ring patch for wideband conical radiation pattern is proposed. To accomplish a low profile with wideband conical radiation characteristics, a stepped cylindrical monopole and a TM41 higher-order mode ring patch with four shorting pins are utilized. The proposed antenna has a monopole-like radiation pattern with a wide 10-dB return loss bandwidth of 11 GHz (2 GHz–13 GHz. It can cover various wireless services, such as wireless broadband (WiBro; 2.3 GHz–2.39 GHz, wireless local area networks (WLAN; 2.4 GHz–2.484 GHz, 5.15 GHz–5.35 GHz, and 5.725 GHz–5.875 GHz, digital multimedia broadcasting (DMB; 2.63 GHz–2.655 GHz, and ultra wideband (UWB; 3.1 GHz–10.6 GHz. The antenna has a height of only 0.12λ0 at 2 GHz.
Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.
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Michael U Gutmann
Full Text Available Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.
Pecka, Shannon; Schmid, Kendra; Pozehl, Bunny
2014-12-01
This article describes development of the Pecka Grading Rubric (PGR) as a strategy to facilitate and evaluate students' higher-order thinking in discussion boards. The purpose of this study was to describe psychometric properties of the PGR. Rubric reliability was pilot tested on a discussion board assignment used by 15 senior student registered nurse anesthetist enrolled in an Advanced Principles of Anesthesia course. Interrater and intrarater reliabilities were tested using an interclass correlation coefficient (ICC) to evaluate absolute agreement of scoring. Raters gave each category a score, scores of the categories were summed, and a total score was calculated for the entire rubric. Interrater (ICC = 0.939, P < .001) and intrarater (ICC = 0.902 to 0.994, P < .001) reliabilities were excellent for total point scores. A content validity index was used to evaluate content validity. Raters evaluated content validity of each cell of the PGR. The content validity index (0.8-1.0) was acceptable. Known-group validity was evaluated by comparing graduate student registered nurse anesthetists (N = 7) with undergraduate senior nursing students (N = 13). Beginning evidence indicates a valid and reliable instrument that measures higher-order thinking in the student registered nurse anesthetist.
Calculating Higher-Order Moments of Phylogenetic Stochastic Mapping Summaries in Linear Time.
Dhar, Amrit; Minin, Vladimir N
2017-05-01
Stochastic mapping is a simulation-based method for probabilistically mapping substitution histories onto phylogenies according to continuous-time Markov models of evolution. This technique can be used to infer properties of the evolutionary process on the phylogeny and, unlike parsimony-based mapping, conditions on the observed data to randomly draw substitution mappings that do not necessarily require the minimum number of events on a tree. Most stochastic mapping applications simulate substitution mappings only to estimate the mean and/or variance of two commonly used mapping summaries: the number of particular types of substitutions (labeled substitution counts) and the time spent in a particular group of states (labeled dwelling times) on the tree. Fast, simulation-free algorithms for calculating the mean of stochastic mapping summaries exist. Importantly, these algorithms scale linearly in the number of tips/leaves of the phylogenetic tree. However, to our knowledge, no such algorithm exists for calculating higher-order moments of stochastic mapping summaries. We present one such simulation-free dynamic programming algorithm that calculates prior and posterior mapping variances and scales linearly in the number of phylogeny tips. Our procedure suggests a general framework that can be used to efficiently compute higher-order moments of stochastic mapping summaries without simulations. We demonstrate the usefulness of our algorithm by extending previously developed statistical tests for rate variation across sites and for detecting evolutionarily conserved regions in genomic sequences.
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S. Sadeghzadeh
Full Text Available Abstract This paper implements the higher order Hamiltonian method to analyze an electrostatically actuated nonlinear micro beam-based micro electro mechanical oscillator. First, second and third approximate solutions are obtained, and the frequency responses of the system are compared with energy balance method solution and previously solved Variational Approach (VA and exact solution. After driving the equation of motion based on the Euler-Bernoulli beam theory, Galerkin method has been used to simplify the nonlinear equation of motion. Higher order Hamiltonian approach has been used to solve the problem and introduce a design strategy. Phase plane diagram of electrostatically actuated micro beam has plotted to show the stability of presented nonlinear system and natural frequencies are calculated to use for resonator design. According to the numerical results, the second approximate is more acceptable and results show that one could obtain a predesign strategy by prediction of effects of mechanical properties and electrical coefficients on the stability and free vibration of common electrostatically actuated micro beam.
HOMOR: higher order model outlier rejection for high b-value MR diffusion data.
Pannek, Kerstin; Raffelt, David; Bell, Christopher; Mathias, Jane L; Rose, Stephen E
2012-11-01
Diffusion MR images are prone to artefacts caused by head movement and cardiac pulsation. Previous techniques for the automated voxel-wise detection of signal intensity outliers have relied on the fit of the diffusion tensor to the data (RESTORE). However, the diffusion tensor cannot appropriately model more than a single fibre population, which may lead to inaccuracies when identifying outlier voxels in crossing fibre regions, particularly when high b-values are used to obtain increased angular contrast. HOMOR (higher order model outlier rejection) was developed to overcome this limitation and is introduced in this study. HOMOR is closely related to RESTORE, but employs a higher order model capable of resolving multiple fibre populations within a voxel. Using high b-value (b=3000 s/mm2) diffusion data from a population of 90 healthy participants, as well as simulations, HOMOR was found to identify a decreased number of outlier voxels compared to RESTORE primarily within areas of crossing, bending and fanning fibres. At lower b-values, however, RESTORE and HOMOR give similar results, which is demonstrated using diffusion data acquired at b=1000 s/mm2 in a mixed cohort. This study demonstrates that, although RESTORE is suitable for low b-value data, HOMOR is better suited for high b-value data. Copyright © 2012 Elsevier Inc. All rights reserved.
Higher order corrections to dust-acoustic shock waves in a strongly coupled cryogenic dusty plasma
El-Borie, M. A.; Atteya, A.
2017-11-01
To investigate the contribution of higher-order nonlinearity and dissipation to nonlinear ultra-low-frequency dust-acoustic shock waves (DASWs), a reductive perturbation technique is employed in a strongly coupled cryogenic dusty plasma. The model consists of Boltzmann distributed electrons and ions, as well as equations for strongly coupled charged dust grains. A nonlinear Burger equation and a linear inhomogeneous Burger-type equation are derived. The present model admits both compressive and rarefactive dust-acoustic (DA) shocks. Including these higher-order corrections results in creating new shock wave structures called "humped DASWs." It is shown that the effects of kinematic viscosity, the number of electrons residing on the dust grain surface, Zd, and the dust number density via β have important roles in the basic features of the produced DA shocks and the associated electric fields. It has been shown that it is more important to be included. These findings are devoted to explaining the observed waves propagating in the laboratory plasma experiments at cryogenic temperature. This kind of plasma is used for etching nano-patterns without defects, used in nonideal systems, and physics of nucleation to deposit nanosize Si compounds.
Diagnosis of broken-bars fault in induction machines using higher order spectral analysis.
Saidi, L; Fnaiech, F; Henao, H; Capolino, G-A; Cirrincione, G
2013-01-01
Detection and identification of induction machine faults through the stator current signal using higher order spectra analysis is presented. This technique is known as motor current signature analysis (MCSA). This paper proposes two higher order spectra techniques, namely the power spectrum and the slices of bi-spectrum used for the analysis of induction machine stator current leading to the detection of electrical failures within the rotor cage. The method has been tested by using both healthy and broken rotor bars cases for an 18.5 kW-220 V/380 V-50 Hz-2 pair of poles induction motor under different load conditions. Experimental signals have been analyzed highlighting that bi-spectrum results show their superiority in the accurate detection of rotor broken bars. Even when the induction machine is rotating at a low level of shaft load (no-load condition), the rotor fault detection is efficient. We will also demonstrate through the analysis and experimental verification, that our proposed proposed-method has better detection performance in terms of receiver operation characteristics (ROC) curves and precision-recall graph. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.
Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping
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Skrollan Stockinger
2013-09-01
Full Text Available A new approach for the investigation of a higher-order reaction by on-column reaction gas chromatography is presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels–Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol. To overcome limitations of short reaction contact times at elevated temperatures a novel experimental setup was developed involving a cooling trap to achieve focusing and mixing of the reactants at a defined spot in a fused-silica capillary. This trap functions as a reactor within the separation column in the oven of a gas chromatograph. The reactants are sequentially injected to avoid undefined mixing in the injection port. An experimental protocol was developed with optimized injection intervals and cooling times to achieve sufficient conversions at short reaction times. Reaction products were rapidly identified by mass spectrometric detection. This new approach represents a practical procedure to investigate higher-order reactions at an analytical level and it simultaneously provides valuable information for the optimization of the reaction conditions.
Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping.
Stockinger, Skrollan; Trapp, Oliver
2013-01-01
A new approach for the investigation of a higher-order reaction by on-column reaction gas chromatography is presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels-Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol. To overcome limitations of short reaction contact times at elevated temperatures a novel experimental setup was developed involving a cooling trap to achieve focusing and mixing of the reactants at a defined spot in a fused-silica capillary. This trap functions as a reactor within the separation column in the oven of a gas chromatograph. The reactants are sequentially injected to avoid undefined mixing in the injection port. An experimental protocol was developed with optimized injection intervals and cooling times to achieve sufficient conversions at short reaction times. Reaction products were rapidly identified by mass spectrometric detection. This new approach represents a practical procedure to investigate higher-order reactions at an analytical level and it simultaneously provides valuable information for the optimization of the reaction conditions.
Roets, Lizeth; Maritz, Jeanette
2017-02-01
International research in nursing education has shown to be deficient regarding both the quality of research produced and the building of disciplinary capacity. The CHENMA (Collaboration for Higher Education of Nurses and Midwives in Africa) project aimed to strengthen nursing and midwifery expertise in Africa. Sixteen French-speaking students of the Democratic Republic of the Congo (DRC) enrolled for a master's degree in nursing midwifery at a South African university in 2008. Ten of the initial 16 students graduated with a master's degree in 2012. One student withdrew and five students completed a postgraduate diploma in midwifery. The objective of this paper is to explore the quality of the output of those master's degree students, namely their dissertation (with specific reference to the demonstration of HOTS). An exploratory, evaluative, single, descriptive case study was utilised. Realist, purposeful sampling was used. Six of the 10 completed final dissertations were evaluated as well as three reflective reports from the supervisor, translator and critical reader. The findings indicated that most dissertations fell below the expected standard, with a paucity of higher-order thinking and application skills. Language, and possibly cultural dynamics, seemed to be the largest barrier to learning and communication. The dissertations lacked conceptual skills, scientific writing skills, logical order of thought and congruency. Analysis of the dissertations revealed a limited ability of novice scholars to explore the nature of information and to interpret and manipulate the data in a novel way. Copyright © 2016 Elsevier Ltd. All rights reserved.