15,994 research outputs found
Analog VLSI neural network integrated circuits
Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit
Assessing Information Literacy Instruction in Selected English Classes At Tennessee State University
In this study, the Brown-Daniel Library located at Tennessee State University (TSU) provided information literacy/bibliographic instruction (IL/BI) to six selected English 1010 classes with a total of 119 students in the spring semester of 2010. Students were administered an online pretest prior to the instructor’s presentation, and administered the same test as a posttest following the lecture. All classes were held on days that allotted one hour and twenty minutes which gave the library faculty time to administer both tests. Students were also asked to evaluate instruction using a Likert-style measure called Library Orientation Survey. All results were electronically submitted to the investigators for analyses
Ergodic property of Markovian semigroups on standard forms of von Neumann algebras
We give sufficient conditions for ergodicity of the Markovian semigroups
associated to Dirichlet forms on standard forms of von Neumann algebras
constructed by the method proposed in Refs. [Par1,Par2]. We apply our result to
show that the diffusion type Markovian semigroups for quantum spin systems are
ergodic in the region of high temperatures where the uniqueness of the
KMS-state holds.Comment: 25 page
Determination of the Binding Site of Adenovirus E4 11K on the Cellular Protein DDX6
Adenovirus is a double-stranded DNA virus that is responsible for localized infections, such as upper respiratory tract infections. The virus takes over the target cell through many mechanisms, in particular taking control of host cell gene expression mechanisms as well as controlling host cell protein synthesis machinery. One of the functions of the adenovirus E4 11k protein is in turning off host cell protein synthesis and regulating late viral gene expression. E4 11k from all adenovirus subclasses has been shown to disrupt cellular RNA processing bodies (P-bodies), and adenovirus serotype 5 has a direct interaction with a P-body protein, Ddx6. Our research goal is the identification of the binding site of Ddx6 on the E4 11k protein. Once this site is narrowed down to a single amino acid or sequence of amino acids, we aim to determine whether or not the binding of E4 11k with Ddx6 and later disruption of P-bodies during an adenovirus infection is involved in the control of host cell and late viral protein synthesis
Quantum Hall Ferromagnets: Induced Topological term and electromagnetic interactions
The quantum Hall ground state in materials like GaAs is well known
to be ferromagnetic in nature. The exchange part of the Coulomb interaction
provides the necessary attractive force to align the electron spins
spontaneously. The gapless Goldstone modes are the angular deviations of the
magnetisation vector from its fixed ground state orientation. Furthermore, the
system is known to support electrically charged spin skyrmion configurations.
It has been claimed in the literature that these skyrmions are fermionic owing
to an induced topological Hopf term in the effective action governing the
Goldstone modes. However, objections have been raised against the method by
which this term has been obtained from the microscopics of the system. In this
article, we use the technique of the derivative expansion to derive, in an
unambiguous manner, the effective action of the angular degrees of freedom,
including the Hopf term. Furthermore, we have coupled perturbative
electromagnetic fields to the microscopic fermionic system in order to study
their effect on the spin excitations. We have obtained an elegant expression
for the electromagnetic coupling of the angular variables describing these spin
excitations.Comment: 23 pages, Plain TeX, no figure
Efficient Bayesian hierarchical functional data analysis with basis function approximations using Gaussian-Wishart processes
Functional data are defined as realizations of random functions (mostly
smooth functions) varying over a continuum, which are usually collected with
measurement errors on discretized grids. In order to accurately smooth noisy
functional observations and deal with the issue of high-dimensional observation
grids, we propose a novel Bayesian method based on the Bayesian hierarchical
model with a Gaussian-Wishart process prior and basis function representations.
We first derive an induced model for the basis-function coefficients of the
functional data, and then use this model to conduct posterior inference through
Markov chain Monte Carlo. Compared to the standard Bayesian inference that
suffers serious computational burden and unstableness for analyzing
high-dimensional functional data, our method greatly improves the computational
scalability and stability, while inheriting the advantage of simultaneously
smoothing raw observations and estimating the mean-covariance functions in a
nonparametric way. In addition, our method can naturally handle functional data
observed on random or uncommon grids. Simulation and real studies demonstrate
that our method produces similar results as the standard Bayesian inference
with low-dimensional common grids, while efficiently smoothing and estimating
functional data with random and high-dimensional observation grids where the
standard Bayesian inference fails. In conclusion, our method can efficiently
smooth and estimate high-dimensional functional data, providing one way to
resolve the curse of dimensionality for Bayesian functional data analysis with
Gaussian-Wishart processes.Comment: Under revie
Stiffness and energy losses in cylindrically symmetric superconductor levitating systems
Stiffness and hysteretic energy losses are calculated for a magnetically
levitating system composed of a type-II superconductor and a permanent magnet
when a small vibration is produced in the system. We consider a cylindrically
symmetric configuration with only vertical movements and calculate the current
profiles under the assumption of the critical state model. The calculations,
based on magnetic energy minimization, take into account the demagnetization
fields inside the superconductor and the actual shape of the applied field. The
dependence of stiffness and hysteretic energy losses upon the different
important parameters of the system such as the superconductor aspect ratio, the
relative size of the superconductor-permanent magnet, and the critical current
of the superconductor are all systematically studied. Finally, in view of the
results, we provide some trends on how a system such as the one studied here
could be designed in order to optimize both the stiffness and the hysteretic
losses.Comment: 8 pages; 8 figure
Josephson surface plasmons in spatially confined cuprate superconductors
In this work, we generalize the theory of localized surface plasmons to the
case of high-Tc cuprate superconductors, spatially confined in the form of
small spherical particles. At variance from ordinary metals, cuprate
superconductors are characterized by a low-energy bulk excitation known as the
Josephson plasma wave (JPW), arising from interlayer tunneling of the
condensate along the c-axis. The effect of the JPW is revealed in a
characteristic spectrum of surface excitations, which we call Josephson surface
plasmons. Our results, which apply to any material with a strongly anisotropic
electromagnetic response, are worked out in detail for the case of multilayered
superconductors supporting both low-frequency (acoustic) and transverse-optical
JPW. Spatial confinement of the Josephson plasma waves may represent a new
degree of freedom to engineer their frequencies and to explore the link between
interlayer tunnelling and high-Tc superconductivity
Chaos in Small-World Networks
A nonlinear small-world network model has been presented to investigate the
effect of nonlinear interaction and time delay on the dynamic properties of
small-world networks. Both numerical simulations and analytical analysis for
networks with time delay and nonlinear interaction show chaotic features in the
system response when nonlinear interaction is strong enough or the length scale
is large enough. In addition, the small-world system may behave very
differently on different scales. Time-delay parameter also has a very strong
effect on properties such as the critical length and response time of
small-world networks
Strain-controlled band engineering and self-doping in ultrathin LaNiO films
We report on a systematic study of the temperature-dependent Hall coefficient
and thermoelectric power in ultra-thin metallic LaNiO films that reveal a
strain-induced, self-doping carrier transition that is inaccessible in the
bulk. As the film strain varies from compressive to tensile at fixed
composition and stoichiometry, the transport coefficients evolve in a manner
strikingly similar to those of bulk hole-doped superconducting cuprates with
varying doping level. Density functional calculations reveal that the
strain-induced changes in the transport properties are due to self-doping in
the low-energy electronic band structure. The results imply that thin-film
epitaxy can serve as a new means to achieve hole-doping in other (negative)
charge-transfer gap transition metal oxides without resorting to chemical
substitution
- …