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

Lithium-diffused solar cells Quarterly report, 1 Jul. - 30 Sep. 1968

Lithium diffused silicon solar cell

Development and fabrication of lithium- diffused silicon solar cells Final report, 18 Aug. - 31 Jan. 1968

Lithium-diffused p-n silicon solar cells of high conversion efficiency and improve resistance to space radiation effect

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

Deformation effects in 56^{56}Ni nuclei produced in 28^{28}Si+28^{28}Si at 112 MeV

Velocity and energy spectra of the light charged particles (protons and $\alpha$-particles) emitted in the $^{28}$Si(E$_{lab}$ = 112 MeV) + $^{28}$Si reaction have been measured at the Strasbourg VIVITRON Tandem facility. The ICARE charged particle multidetector array was used to obtain exclusive spectra of the light particles in the angular range 15 - 150 degree and to determine the angular correlations of these particles with respect to the emission angles of the evaporation residues. The experimental data are analysed in the framework of the statistical model. The exclusive energy spectra of $\alpha$-particles emitted from the $^{28}$Si + $^{28}$Si compound system are generally well reproduced by Monte Carlo calculations using spin-dependent level densities. This spin dependence approach suggests the onset of large deformations at high spin. A re-analysis of previous $\alpha$-particle data from the $^{30}$Si + $^{30}$Si compound system, using the same spin-dependent parametrization, is also presented in the framework of a general discussion of the occurrence of large deformation effects in the A$_{CN}$ ~ 60 mass region.Comment: 25 pages, 6 figure

Landau damping in trapped Bose-condensed gases

We study Landau damping in dilute Bose-Einstein condensed gases in both spherical and prolate ellipsoidal harmonic traps. We solve the Bogoliubov equations for the mode spectrum in both of these cases, and calculate the damping by summing over transitions between excited quasiparticle states. The results for the spherical case are compared to those obtained in the Hartree-Fock approximation, where the excitations take on a single-particle character, and excellent agreement between the two approaches is found. We have also taken the semiclassical limit of the Hartree-Fock approximation and obtain a novel expression for the Landau damping rate involving the time dependent self-diffusion function of the thermal cloud. As a final approach, we study the decay of a condensate mode by making use of dynamical simulations in which both the condensate and thermal cloud are evolved explicitly as a function of time. A detailed comparison of all these methods over a wide range of sample sizes and trap geometries is presented.Comment: 18 pages, 13 figures, submitted to the New Journal of Physics focus issue on Quantum Gase

Role of deformation in the decay of 56^{56}Ni and 40^{40}Ca di-nuclei

Inclusive as well as exclusive energy spectra of the light charged particles emitted in the $^{28}Si(E_{lab}=112.6 MeV) + ^{28}Si,^{12}C$ 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 $\alpha$-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) -