2,821 research outputs found
Ion-induced nucleation. II. Polarizable multipolar molecules
Density functional theory is applied to ion-induced nucleation of polarizable multipolar molecules. The asymmetric nature of the ion-molecule interaction is shown to cause the sign preference in ion-induced nucleation. When the ion-molecule interaction is weak, the observed sign preference is consistent with that of the bare ion-molecule interaction potential and decreases with increasing supersaturation. However, as the ion-molecule interaction becomes stronger, the sign preference in the reversible work exhibits some nontrivial behavior. For molecular parameters applicable for CS2 and CH4, the predicted values of the reversible work of nucleation depend on the sign of the ion charge, yielding a difference in the nucleation rate by factors of 10 to 10^(2) and 10 to 10^(5), respectively
De Branges spaces and Krein's theory of entire operators
This work presents a contemporary treatment of Krein's entire operators with
deficiency indices and de Branges' Hilbert spaces of entire functions.
Each of these theories played a central role in the research of both renown
mathematicians. Remarkably, entire operators and de Branges spaces are
intimately connected and the interplay between them has had an impact in both
spectral theory and the theory of functions. This work exhibits the
interrelation between Krein's and de Branges' theories by means of a functional
model and discusses recent developments, giving illustrations of the main
objects and applications to the spectral theory of difference and differential
operators.Comment: 37 pages, no figures. The abstract was extended. Typographical errors
were corrected. The bibliography style was change
Hardy's proof of nonlocality in the presence of noise
We extend the validity of Hardy's nonlocality without inequalities proof to
cover the case of special one-parameter classes of non-pure statistical
operators. These mixed states are obtained by mixing the Hardy states with a
completely chaotic noise or with a colored noise and they represent a realistic
description of imperfect preparation processes of (pure) Hardy states in
nonlocality experiments. Within such a framework we are able to exhibit a
precise range of values of the parameter measuring the noise affecting the
non-optimal preparation of an arbitrary Hardy state, for which it is still
possible to put into evidence genuine nonlocal effects. Equivalently, our work
exhibits particular classes of bipartite mixed states whose constituents do not
admit any local and deterministic hidden variable model reproducing the quantum
mechanical predictions.Comment: 9 pages, 2 figures, RevTex, revised versio
Ontological Relativity reconsidered: Quine on Löwenheim-Skolem, Davidson on Quine
In view of the dramatic contrast between speculative thought dressed in fashionable jargon and Quine's sober accounts of the scientific status quo it might seem frivolous even to suggest that his work exhibits a postmodern touch. The present paper will, nevertheless, focus on Quine's usage of the Löwenheim-Skolem theorems as a prominent example of ontological relativity and will attempt to show that Quine's treatment is unattractive to philosophers of mathematics and -- more generally -- untenable within the very methodology arising from Quine's basic approach. After examining the doctrine of relativity as applied to the Löwenheim-Skolem result two recent reflections on it's theoretical impact will be discussed. Those contributions make a strong case against the kind of attitude exemplified by Quine, but they do not address the general issue of how to deal with relativism. Donald Davidson has provided a remarkably attractive strategy to counter relativistic moves. Stripping away postmodernist pretensions this strategy challenges the peculiar Quinean mix of methodological austerity and anti-foundationalism
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Infinite majesty : disabled and athletic métis in David Foster Wallace’s tennis writing
As John Jeremiah Sullivan remarks in his introduction to String Theory, a collection of David Foster Wallace’s essays on tennis, tennis “may be [Wallace’s] most consistent theme at the surface level.” As once an elite junior professional himself, Wallace reflects on and writes from his own involvement in the sport, with the conditioning, strategy, and body-mind training that goes into it. In other essays of String Theory, Wallace reaches beyond his personal playing experience, observes professional tennis players with their incredible grace, and creates his own tennis playing students in Infinite Jest. Throughout these fictional and nonfictional accounts, he conceptualizes what such eminent athleticism entails. This paper will show that celebrated athleticism in Wallace’s work exhibits an embodimental métis, or an acute, crafty body-mind knowledge of its movement through space. Beyond only characterizing athletic movement, however, this paper argues that the same concept of métis extends to people with disabilities, including characters with disabilities in Infinite Jest. The same hyperawareness of corporeality, versatile methods of adjusting to oppositional contexts, and extraordinary complexity are shared by both groups. Using rhetorical scholarship on métis and disability theories of embodiment and social representation, this paper will draw parallels between the moving body-minds of athletic and disabled bodies and trace the implications of this analogy for Wallace’s work and disability studies.Englis
Distributed Learning over Unreliable Networks
Most of today's distributed machine learning systems assume {\em reliable
networks}: whenever two machines exchange information (e.g., gradients or
models), the network should guarantee the delivery of the message. At the same
time, recent work exhibits the impressive tolerance of machine learning
algorithms to errors or noise arising from relaxed communication or
synchronization. In this paper, we connect these two trends, and consider the
following question: {\em Can we design machine learning systems that are
tolerant to network unreliability during training?} With this motivation, we
focus on a theoretical problem of independent interest---given a standard
distributed parameter server architecture, if every communication between the
worker and the server has a non-zero probability of being dropped, does
there exist an algorithm that still converges, and at what speed? The technical
contribution of this paper is a novel theoretical analysis proving that
distributed learning over unreliable network can achieve comparable convergence
rate to centralized or distributed learning over reliable networks. Further, we
prove that the influence of the packet drop rate diminishes with the growth of
the number of \textcolor{black}{parameter servers}. We map this theoretical
result onto a real-world scenario, training deep neural networks over an
unreliable network layer, and conduct network simulation to validate the system
improvement by allowing the networks to be unreliable
Landau thermodynamic potential for BaTiO_3
In the paper, the description of the dielectric and ferroelectric properties
of BaTiO_3 single crystals using Landau thermodynamic potential is addressed.
Our results suggest that when using the sixth-power free energy expansion of
the thermodynamic potential, remarkably different values of the fourth-power
coefficient, \beta (the coefficient of P^4_i terms), are required to adequately
reproduce the nonlinear dielectric behavior of the paraelectric phase and the
electric field induced ferroelectric phase, respectively. In contrast, the
eighth-power expansion with a common set of coefficients enables a good
description for both phases at the same time. These features, together with the
data available in literature, strongly attest to the necessity of the
eighth-power terms in Landau thermodynamic potential of BaTiO_3. In addition,
the fourth-power coefficients, \beta and \xi (the coefficient of P^2_i P^2_j
terms), were evaluated from the nonlinear dielectric responses along [001],
[011], and [111] orientations in the paraelectric phase. Appreciable
temperature dependence was evidenced for both coefficients above T_C. Further
analysis on the linear dielectric response of the single domain crystal in the
tetragonal phase demonstrated that temperature dependent anharmonic
coefficients are also necessary for an adequate description of the dielectric
behavior in the ferroelectric phase. As a consequence, an eighth-power
thermodynamic potential, with some of the anharmonic coefficients being
temperature dependent, was proposed and compared with the existing potentials.
In general, the potential proposed in this work exhibits a higher quality in
reproducing the dielectric and ferroelectric properties of this prototypic
ferroelectric substance.Comment: 7 figures, 5 table
A temperature independent driver for Mach-Zehnder modulators
This paper describes a fully differential inductorlesstemperature independent laser driver for a Mach-Zehndermodulator (MZM). The laser driver in this work exhibits robustnessin bandwidth and gain across the temperature range27oC to 135oC. This driver (fabricated using a 130nm CMOSprocess) can achieve a differential output voltage swing of up to4Vpp when driving a 50 Ohm Load at speeds of up to 12.5Gb/sacross a temperature range 27oC to 135oC
HYPERPROPERTIES-BASED OPTICAL FLOW-BASED AUTONOMOUS DRIVING SYSTEM
This study presents an autonomous driving system based on the principles of trace vectors derived from hyperproperty of a modified optical flowalgorithm. This technique allows keeping track of the past motion vectors by tracking the constraint sets to overcome the non-linear attributes ofthe deformable feature points and motion vectors. The results presented in this work exhibits stable tracking and multi-step prediction in a limitednumber of steps with less training vectors
Dayton Athletic Department: Creative Services Project
During my role as the Athletic Department’s Creative Services Intern, I worked along side the Assistant Creative Director. I helped the Assistant Creative Director specifically with Graphic Design for Dayton’s Winter and Spring sports teams. I assisted with the creation of print and digital collateral utilizing InDesign, Photoshop, and Illustrator. I helped creating marketing fliers, game programs, and game day video board graphics. I also helped design for social media accounts including Facebook, Twitter and Instagram. This work exhibits what I accomplished the past several months.https://ecommons.udayton.edu/stander_posters/1993/thumbnail.jp
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