464 research outputs found
Development of radiation hardened lithium- doped solar cells Final report
Fabrication techniques to improve initial efficiency and radiation tolerance of radiation hardened lithium-diffused silicon solar cell
The Effects of Listening Training on Achievement
Reading has long been recognized as a necessary skill but only recently has there been much interest in listening skills even though listening is the most frequently used language activity. Within the past decade many studies have indicated that listening ability correlates highly with intelligence, vocabulary, and report card grades, and some investigators claim that listening training will improve listening ability. If listening ability correlates positively with report card grades then listening training should aid academic achievement.
The present experiment has investigated the effect of listening training on the grade point averages of college freshmen. Since special treatment of experimental subjects can influence the subjects performance an additional control group, called the Hawthorne group, was added to this experiment. This Hawthorne group was given special attention by personal study assignments while the experimental group listened to tape recorded listening exercises. The control group was not told that they were part of the experiment.
An analysis of variance revealed that there was a significant difference among the groups and a further analysis was made and the variability was localized. A significant difference was found between the listening training and control groups but no significant difference was found between the Hawthorne group and either the control group or the listening training group. Based on these results it is indicated that the Hawthorne Effect and listening training are simply different levels of the same variable
Neurogenesis Deep Learning
Neural machine learning methods, such as deep neural networks (DNN), have
achieved remarkable success in a number of complex data processing tasks. These
methods have arguably had their strongest impact on tasks such as image and
audio processing - data processing domains in which humans have long held clear
advantages over conventional algorithms. In contrast to biological neural
systems, which are capable of learning continuously, deep artificial networks
have a limited ability for incorporating new information in an already trained
network. As a result, methods for continuous learning are potentially highly
impactful in enabling the application of deep networks to dynamic data sets.
Here, inspired by the process of adult neurogenesis in the hippocampus, we
explore the potential for adding new neurons to deep layers of artificial
neural networks in order to facilitate their acquisition of novel information
while preserving previously trained data representations. Our results on the
MNIST handwritten digit dataset and the NIST SD 19 dataset, which includes
lower and upper case letters and digits, demonstrate that neurogenesis is well
suited for addressing the stability-plasticity dilemma that has long challenged
adaptive machine learning algorithms.Comment: 8 pages, 8 figures, Accepted to 2017 International Joint Conference
on Neural Networks (IJCNN 2017
A new chelonioid turtle from the Paleocene of Cabinda, Angola
Sem PDF.We report a new chelonioid turtle on the basis of a nearly complete skull collected in lower Paleocene, shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda Province, Angola. Chelonioid material previously reported from this locality is likely referable to this new taxon. The well-preserved skull is missing the left quadrate, squamosal, and prootic, both opisthotics, and the mandible. The skull possesses a rod-like basisphenoid rostrum, which is a synapomorphy of Chelonioidea, but it differs from other chelonioid skulls in that the contact between the parietal and squamosal is absent, and the posterior palatine foramen is present. Phylogenetic analysis recovers the new taxon as a basal chelonioid. The Paleocenetextendash Eocene strata near Landana have produced a wealth of turtle fossils, including the holotype of the pleurodire Taphrosphys congolensis. A turtle humerus collected from the Landana locality differs morphologically from the humeri of chelonioids and Taphrosphys, indicating the presence of a third taxon. Chelonioid fossil material in the Landana assemblage is rare compared to the abundant fragmentary remains of Taphrosphys that are found throughout the stratigraphic section. This disparity in abundance suggests the new chelonioid taxon preferred open marine habitats, whereas Taphrosphys frequented nearshore environments.publishe
A Digital Neuromorphic Architecture Efficiently Facilitating Complex Synaptic Response Functions Applied to Liquid State Machines
Information in neural networks is represented as weighted connections, or
synapses, between neurons. This poses a problem as the primary computational
bottleneck for neural networks is the vector-matrix multiply when inputs are
multiplied by the neural network weights. Conventional processing architectures
are not well suited for simulating neural networks, often requiring large
amounts of energy and time. Additionally, synapses in biological neural
networks are not binary connections, but exhibit a nonlinear response function
as neurotransmitters are emitted and diffuse between neurons. Inspired by
neuroscience principles, we present a digital neuromorphic architecture, the
Spiking Temporal Processing Unit (STPU), capable of modeling arbitrary complex
synaptic response functions without requiring additional hardware components.
We consider the paradigm of spiking neurons with temporally coded information
as opposed to non-spiking rate coded neurons used in most neural networks. In
this paradigm we examine liquid state machines applied to speech recognition
and show how a liquid state machine with temporal dynamics maps onto the
STPU-demonstrating the flexibility and efficiency of the STPU for instantiating
neural algorithms.Comment: 8 pages, 4 Figures, Preprint of 2017 IJCN
Role of deformation in the decay of Ni and Ca di-nuclei
Inclusive as well as exclusive energy spectra of the light charged particles
emitted in the reactions have
been measured at the Strasbourg VIVITRON facility in the angular range 15^0 -
150^0, using the ICARE multidetector array. The experimental energy spectra of
-particles are generally well reproduced by the statistical model with
a spin-dependent level density indicating the onset of defomations at high
spin.Comment: 4 pages, 2 ps Figures included -- Talk given at the International
Nuclear Physics Conference INPC98, Paris, France, August, 1998 (Proceedings
to be published in Nuclear Physics A, 1999) -
Modelling the transient processes produced under heavy particle irradiation
A new model for the thermal spike produced by the nuclear energy loss, as
source of transient processes, is derived analytically, for power law
dependences of the diffusivity on temperature, as solution of the heat
equation. The contribution of the ionizing energy loss to the spike is not
included. The range of validity of the model is analysed, and the results are
compared with numerical solutions obtained in the frame of the previous model
of the authors, which takes into account both nuclear and ionization energy
losses, as well as the coupling between the two subsystems in crystalline
semiconductors. Particular solutions are discussed and the errors induced by
these approximations are analysed.Comment: 13 page
Novel diffusion mechanism on the GaAs(001) surface: the role of adatom-dimer interaction
Employing first principles total energy calculations we have studied the
behavior of Ga and Al adatoms on the GaAs(001)-beta2 surface. The adsorption
site and two relevant diffusion channels are identified. The channels are
characterized by different adatom-surface dimer interaction. Both affect in a
novel way the adatom migration: in one channel the diffusing adatom jumps
across the surface dimers and leaves the dimer bonds intact, in the other one
the surface dimer bonds are broken. The two channels are taken into account to
derive effective adatom diffusion barriers. From the diffusion barriers we
conclude a strong diffusion anisotropy for both Al and Ga adatoms with the
direction of fastest diffusion parallel to the surface dimers. In agreement
with experimental observations we find higher diffusion barriers for Al than
for Ga.Comment: 4 pages, 2 figures, Phys. Rev. Lett. 79 (1997). Other related
publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm
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