167 research outputs found
On simultaneous representations of primes by binary quadratic forms
AbstractLet p ⥠± 1 (mod 8) be a prime which is a quadratic residue modulo 7. Then p = M2 + 7N2, and knowing M and N makes it possible to âpredictâ whether p = A2 + 14B2 is solvable or p = 7C2 + 2D2 is solvable. More generally, let q and r be distinct primes, and let an integral solution of H2p = M2 + qN2 be known. Under appropriate assumptions, this information can be used to restrict the possible values of K for which K2q = A2 + qrB2 is solvable and the possible values of KâČ for which KâČ2p = qC2 + rD2 is solvable. These restrictions exclude some of the binary quadratic forms in the principal genus of discriminant â4qr from representing p
A systematic review of quality of student experience in higher education
Purpose: The purpose of this paper is to identify and synthesize major streams of research on quality of student experience in higher education, in order to present an agenda for future research.
Design/methodology/approach: A systematic review of high quality journals published during the period 2000 to 2014 in the areas of quality of student experience and higher education was performed.
Findings: Findings highlight current research trends on the quality of student experience in higher education. Results show five prevailing research streams: 1) exploration of learning experience; 2) exploration of student experience; 3) gender differences in assessment of higher education experience; 4) improvement in quality of student experience, 5) student satisfaction with higher education experience.
Research limitations/implications: The identification of the five research streams presented in the findings of this paper provide the basis for a synthesis of key issues identified within each research stream. These discussions, along with the identification of the purposes and limitations of existential research allow existential issues concerning research on quality of student experience in higher education to be addressed.
Practical implications: Literature currently portrays the quality of student experience as a student-centric idea. Together with the purposes and limitations identified in existing research, the paper proposes an agenda for future research that increases the variety of research streams that is essential to provide a deeper understanding of the student experience to enhance the delivery of quality in higher education.
Originality/value: The findings contribute to the research scene by providing important insights in terms of the current trends and focus of existing research in the area of quality of student experience in higher education
Moving boundary approximation for curved streamer ionization fronts: Solvability analysis
The minimal density model for negative streamer ionization fronts is
investigated. An earlier moving boundary approximation for this model consisted
of a "kinetic undercooling" type boundary condition in a Laplacian growth
problem of Hele-Shaw type. Here we derive a curvature correction to the moving
boundary approximation that resembles surface tension. The calculation is based
on solvability analysis with unconventional features, namely, there are three
relevant zero modes of the adjoint operator, one of them diverging;
furthermore, the inner/outer matching ahead of the front has to be performed on
a line rather than on an extended region; and the whole calculation can be
performed analytically. The analysis reveals a relation between the fields
ahead and behind a slowly evolving curved front, the curvature and the
generated conductivity. This relation forces us to give up the ideal
conductivity approximation, and we suggest to replace it by a constant
conductivity approximation. This implies that the electric potential in the
streamer interior is no longer constant but solves a Laplace equation; this
leads to a Muskat-type problem.Comment: 22 pages, 6 figure
Understanding the relationships between tourists\u27 emotional experiences, perceived overall image, satisfaction, and intention to recommend
The purpose of this study is to empirically test an integrative model linking touristsâ emotional experiences, perceived overall image, satisfaction, and intention to recommend. The model was tested using data collected from domestic tourists visiting Sardinia, Italy. Results show that touristsâ emotional experiences act as antecedents of perceived overall image and satisfaction evaluations. In addition, overall image has a positive influence on tourist satisfaction and intention to recommend. The study expands current theorizations by examining the merits of emotions in tourist behavior models. From a practical perspective, the study offers important implications for destination marketers
Positive Integers Represented by Regular Primitive Positive-Definite Integral Ternary Quadratic Forms
In 1997 Jagy, Kaplansky and Schiemann determined that there are at most 913 (classes of) primitive, positive-definite, integral ternary quadratic forms ax2 + by2 + cz2 + dyz + ezx + fxy which are regular. In this paper the positive integers represented by these 913 ternary forms are given
Fluid Flows of Mixed Regimes in Porous Media
In porous media, there are three known regimes of fluid flows, namely,
pre-Darcy, Darcy and post-Darcy. Because of their different natures, these are
usually treated separately in literature. To study complex flows when all three
regimes may be present in different portions of a same domain, we use a single
equation of motion to unify them. Several scenarios and models are then
considered for slightly compressible fluids. A nonlinear parabolic equation for
the pressure is derived, which is degenerate when the pressure gradient is
either small or large. We estimate the pressure and its gradient for all time
in terms of initial and boundary data. We also obtain their particular bounds
for large time which depend on the asymptotic behavior of the boundary data but
not on the initial one. Moreover, the continuous dependence of the solutions on
initial and boundary data, and the structural stability for the equation are
established.Comment: 33 page
Logarithmic diffusion and porous media equations: a unified description
In this work we present the logarithmic diffusion equation as a limit case
when the index that characterizes a nonlinear Fokker-Planck equation, in its
diffusive term, goes to zero. A linear drift and a source term are considered
in this equation. Its solution has a lorentzian form, consequently this
equation characterizes a super diffusion like a L\'evy kind. In addition is
obtained an equation that unifies the porous media and the logarithmic
diffusion equations, including a generalized diffusion equation in fractal
dimension. This unification is performed in the nonextensive thermostatistics
context and increases the possibilities about the description of anomalous
diffusive processes.Comment: 5 pages. To appear in Phys. Rev.
Understanding the Relationships between Touristsâ Emotional Experiences, Perceived Overall Image, Satisfaction, and Intention to Recommend
The purpose of this study is to empirically test an integrative model linking tourists' emotional experiences, perceived overall image, satisfaction, and intention to recommend. The model was tested using data collected from domestic tourists visiting Sardinia, Italy. Results show that tourists' emotional experiences act as antecedents of perceived overall image and satisfaction evaluations. In addition, overall image has a positive influence on tourist satisfaction and intention to recommend. The study expands current theorizations by examining the merits of emotions in tourist behavior models. From a practical perspective, the study offers important implications for destination marketers
Radio-frequency dressed state potentials for neutral atoms
Potentials for atoms can be created by external fields acting on properties
like magnetic moment, charge, polarizability, or by oscillating fields which
couple internal states. The most prominent realization of the latter is the
optical dipole potential formed by coupling ground and electronically excited
states of an atom with light. Here we present an experimental investigation of
the remarkable properties of potentials derived from radio-frequency (RF)
coupling between electronic ground states. The coupling is magnetic and the
vector character allows to design state dependent potential landscapes. On atom
chips this enables robust coherent atom manipulation on much smaller spatial
scales than possible with static fields alone. We find no additional heating or
collisional loss up to densities approaching atoms / cm compared
to static magnetic traps. We demonstrate the creation of Bose-Einstein
condensates in RF potentials and investigate the difference in the interference
between two independently created and two coherently split condensates in
identical traps. All together this makes RF dressing a powerful new tool for
micro manipulation of atomic and molecular systems
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