3,869 research outputs found
Exploring the value of trust between teams of special education teachers and paraprofessionals
This phenomenological study explores the value of trust between teams of special education teachers and paraprofessionals. The study delves into their lived experiences, focusing on characteristics and behaviors that build, sustain, destroy and restore trust between them. There are multiple studies on trust in education, however, there is relatively little literature published on the value of trust among individuals committed to providing support for transition-aged students within various Los Angeles County school districts. Existing theories and models on trust have similar characteristics that span across diverse industries. As a result, clear-cut guidelines have enabled members of a team to be aware of how trust impacts their working environment. Purposive sampling provided teams of special education professionals who possessed a depth of knowledge of the subject matter and experience in the classroom. Individual face-to-face, semi-structured interviews were conducted with 12 participants focusing on how they make meaning of the role and value of trust with their special education colleagues. As a result, 165 coded passages were grouped into the following nine themes: (a) characteristics of a trustworthy colleague, (b) importance of trust, (c) outcome of trust, (d) outcome of a lack of trust, (e) building trust, (f) sustaining trust, (g) destroying trust and (h) restoring trust. Two study conclusions emerged. Conclusion one, trust increases communication, respect and collaboration between special education colleagues, as well as enhances student success. Conclusion two, a lack of trust negatively impacts the special education environment, as well as relevant stakeholders, which include: students, parents, special education teachers, paraprofessionals and administrators. Recommendations include participation in team development trainings, as well as personal and professional development that focus on acquiring the characteristics of a trustworthy colleague. Additionally, special education professionals benefit from establishing a shared primary focus of student success. Moreover, the onus of setting the tone of trust falls on the special education teacher. Lastly, special education professionals should relinquish the characteristics that diminish trust. This study provides researchers and professionals in the field of special education with insight into the tools needed to have better working relationships so that they can effectively serve special needs students
On the electrical properties of transparent electrodes
In this paper we present the electrical properties of the typical transparent electrodes (ITO, AZO, IZO, FTO, PEDOT:PSS, etc.) prepared by different methods such as: spray pyrolysis, sputtering, sol-gel, thermal oxidation, PLD, etc. The modifications of electrical properties of electrodes during the sun exposure of the devices may explain some of problems arising in the I-V characterization of third-generation solar cells. The electrical resistivity stability of transparent electrode thin films as a function of the temperature is analysed in detail
The numerical solution of forward–backward differential equations: Decomposition and related issues
NOTICE: this is the author’s version of a work that was accepted for publication in Journal of computational and applied mathematics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of computational and applied mathematics, 234,(2010), doi: 10.1016/j.cam.2010.01.039This journal article discusses the decomposition, by numerical methods, of solutions to mixed-type functional differential equations (MFDEs) into sums of “forward” solutions and “backward” solutions
Role of pseudospin in quasiparticle interferences in epitaxial graphene probed by high-resolution scanning tunneling microscopy
Pseudospin, an additional degree of freedom related to the honeycomb
structure of graphene, is responsible of many of the outstanding electronic
properties found in this material. This article provides a clear understanding
of how such pseudospin impacts the quasiparticle interferences of monolayer
(ML) and bilayer (BL) graphene measured by low temperature scanning tunneling
microscopy and spectroscopy. We have used this technique to map, with very high
energy and space resolution, the spatial modulations of the local density of
states of ML and BL graphene epitaxialy grown on SiC(0001), in presence of
native disorder. We perform a Fourier transform analysis of such modulations
including wavevectors up to unit-vectors of the reciprocal lattice. Our data
demonstrate that the quasiparticle interferences associated to some particular
scattering processes are suppressed in ML graphene, but not in BL graphene.
Most importantly, interferences with 2qF wavevector associated to intravalley
backscattering are not measured in ML graphene, even on the images with highest
resolution. In order to clarify the role of the pseudospin on the quasiparticle
interferences, we use a simple model which nicely captures the main features
observed on our data. The model unambiguously shows that graphene's pseudospin
is responsible for such suppression of quasiparticle interferences features in
ML graphene, in particular for those with 2qF wavevector. It also confirms
scanning tunneling microscopy as a unique technique to probe the pseudospin in
graphene samples in real space with nanometer precision. Finally, we show that
such observations are robust with energy and obtain with great accuracy the
dispersion of the \pi-bands for both ML and BL graphene in the vicinity of the
Fermi level, extracting their main tight binding parameters
A Calibrated Time Domain Envelope Measurement System for the Behavioral Modeling of Power Amplifiers
This paper presents a set-up which enables the generation and the calibrated time domain measurements of complex envelopes of modulated signals at both ports of non linear microwave power amplifiers. The architecture of the characterization tool is given. Examples of error corrected time domain envelopes at the input / output RF ports of a 36 dBm output power – 30dB power gain L-band SSPA are shown. Futhermore, the use of this characterization tool and a suitable processing of measurement data are applied to a novel measurement based behavioral modeling approach of non linear devices accounting for memory effects
Molecular and behavioural evidence for gene flow between host races of the larch budmoth Zeiraphera diniana
Larch and pine associated populations of Zeiraphera diniana (Lepidoptera: Tortricidae) differ
in a number of heritable traits, but pheromone-mediated cross-attraction occurs between
them in the wild. Using a quartet mate choice design (one male and one female of each type
per cage) we estimate that, following cross-attraction by pheromones, the subsequent
probability of hybridization is approximately 28%. We also examined molecular data, and
were unable to distinguish between the races on the basis of 695bp of mitochondrial COI,
tRNA-leucine, and COII gene sequence. Both results support earlier field studies suggesting
that larch- and pine-feeding populations are host races that hybridize at an appreciable level
in the wild. The shared mitochondrial haplotypes we observed are also consistent with
ongoing and successful gene flow between the two host races
Generating Entangled Microwave Radiation Over Two Transmission Lines
Using a superconducting circuit, the Josephson mixer, we demonstrate the
first experimental realization of spatially separated two-mode squeezed states
of microwave light. Driven by a pump tone, a first Josephson mixer generates,
out of quantum vacuum, a pair of entangled fields at different frequencies on
separate transmission lines. A second mixer, driven by a -phase shifted
copy of the first pump tone, recombines and disentangles the two fields. The
resulting output noise level is measured to be lower than for vacuum state at
the input of the second mixer, an unambiguous proof of entanglement. Moreover,
the output noise level provides a direct, quantitative measure of entanglement,
leading here to the demonstration of 6 Mebit.s (Mega entangled bits per
second) generated by the first mixer.Comment: 5 pages, 4 figures. Supplementary Information can be found here as an
ancillary fil
Viriato: a Fourier-Hermite spectral code for strongly magnetised fluid-kinetic plasma dynamics
We report on the algorithms and numerical methods used in Viriato, a novel
fluid-kinetic code that solves two distinct sets of equations: (i) the Kinetic
Reduced Electron Heating Model (KREHM) equations [Zocco & Schekochihin, Phys.
Plasmas 18, 102309 (2011)] (which reduce to the standard Reduced-MHD equations
in the appropriate limit) and (ii) the kinetic reduced MHD (KRMHD) equations
[Schekochihin et al., Astrophys. J. Suppl. 182:310 (2009)]. Two main
applications of these equations are magnetised (Alfvenic) plasma turbulence and
magnetic reconnection. Viriato uses operator splitting (Strang or Godunov) to
separate the dynamics parallel and perpendicular to the ambient magnetic field
(assumed strong). Along the magnetic field, Viriato allows for either a
second-order accurate MacCormack method or, for higher accuracy, a
spectral-like scheme composed of the combination of a total variation
diminishing (TVD) third order Runge-Kutta method for the time derivative with a
7th order upwind scheme for the fluxes. Perpendicular to the field Viriato is
pseudo-spectral, and the time integration is performed by means of an iterative
predictor-corrector scheme. In addition, a distinctive feature of Viriato is
its spectral representation of the parallel velocity-space dependence, achieved
by means of a Hermite representation of the perturbed distribution function. A
series of linear and nonlinear benchmarks and tests are presented, including a
detailed analysis of 2D and 3D Orszag-Tang-type decaying turbulence, both in
fluid and kinetic regimes.Comment: 42 pages, 15 figures, submitted to J. Comp. Phy
Semantic 3D scene interpretation: A framework combining optimal neighborhood size selection with relevant features
3D scene analysis by automatically assigning 3D points a semantic label has become an issue of major interest in recent years. Whereas the tasks of feature extraction and classification have been in the focus of research, the idea of using only relevant and more distinctive features extracted from optimal 3D neighborhoods has only rarely been addressed in 3D lidar data processing. In this paper, we focus on the interleaved issue of extracting relevant, but not redundant features and increasing their distinctiveness by considering the respective optimal 3D neighborhood of each individual 3D point. We present a new, fully automatic and versatile framework consisting of four successive steps: (i) optimal neighborhood size selection, (ii) feature extraction, (iii) feature selection, and (iv) classification. In a detailed evaluation which involves 5 different neighborhood definitions, 21 features, 6 approaches for feature subset selection and 2 different classifiers, we demonstrate that optimal neighborhoods for individual 3D points significantly improve the results of scene interpretation and that the selection of adequate feature subsets may even further increase the quality of the derived results
Quantum Heating of a nonlinear resonator probed by a superconducting qubit
We measure the quantum fluctuations of a pumped nonlinear resonator, using a
superconducting artificial atom as an in-situ probe. The qubit excitation
spectrum gives access to the frequency and temperature of the intracavity field
fluctuations. These are found to be in agreement with theoretical predictions;
in particular we experimentally observe the phenomenon of quantum heating
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