1,359 research outputs found
Asynchronous Graph Pattern Matching on Multiprocessor Systems
Pattern matching on large graphs is the foundation for a variety of
application domains. Strict latency requirements and continuously increasing
graph sizes demand the usage of highly parallel in-memory graph processing
engines that need to consider non-uniform memory access (NUMA) and concurrency
issues to scale up on modern multiprocessor systems. To tackle these aspects,
graph partitioning becomes increasingly important. Hence, we present a
technique to process graph pattern matching on NUMA systems in this paper. As a
scalable pattern matching processing infrastructure, we leverage a
data-oriented architecture that preserves data locality and minimizes
concurrency-related bottlenecks on NUMA systems. We show in detail, how graph
pattern matching can be asynchronously processed on a multiprocessor system.Comment: 14 Pages, Extended version for ADBIS 201
Method to determine defect positions below a metal surface by STM
The oscillatory voltage dependence of the conductance of a quantum point
contact in the presence of a single point-like defect has been analyzed
theoretically. Such signals are detectable and may be exploited to obtain
information on defect positions below a metal surface. Both tunnel junctions
and ballistic contacts of adiabatic shape have been considered. The effect of
quantum interference has been taking into account between the principal wave
that is directly transmitted through the contact and the partial wave that is
scattered by the contact and the defect. This effect leads to oscillations of
the conductance as a function of applied voltage. We obtain the dependence of
the period and amplitude of the conductance oscillations on the position of the
defect inside the metal.Comment: 16 pages, 7 figure
Signature of Fermi surface anisotropy in point contact conductance in the presence of defects
In a previous paper (Avotina et al.,Phys. Rev. B Vol.71, 115430 (2005)) we
have shown that in principle it is possible to image the defect positions below
a metal surface by means of a scanning tunnelling microscope. The principle
relies on the interference of electron waves scattered on the defects, which
give rise to small but measurable conductance fluctuations. Whereas in that
work the band structure was assumed to be free-electron like, here we
investigate the effects of Fermi surface anisotropy. We demonstrate that the
amplitude and period of the conductance oscillations are determined by the
local geometry of the Fermi surface. The signal results from those points for
which the electron velocity is directed along the vector connecting the point
contact to the defect. For a general Fermi surface geometry the position of the
maximum amplitude of the conductance oscillations is not found for the tip
directly above the defect. We have determined optimal conditions for
determination of defect positions in metals with closed and open Fermi
surfaces.Comment: 23 pages, 8 figure
Observation of electronic and atomic shell effects in gold nanowires
The formation of gold nanowires in vacuum at room temperature reveals a
periodic spectrum of exceptionally stable diameters. This is identified as
shell structure similar to that which was recently discovered for alkali metals
at low temperatures. The gold nanowires present two competing `magic' series of
stable diameters, one governed by electronic structure and the other by the
atomic packing.Comment: 4 pages, 4 figure
Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides
The tyrosine-(M)210 of the reaction center of Rhodobacter sphaeroides 2.4.1 has been changed to a tryptophan using site-directed mutagenesis. The reaction center of this mutant has been characterized by low-temperature absorption and fluorescence spectroscopy, time-resolved sub-picosecond spectroscopy, and magnetic resonance spectroscopy. The charge separation process showed bi-exponential kinetics at room temperature, with a main time constant of 36 ps and an additional fast time constant of 5.1 ps. Temperature dependent fluorescence measurements predict that the lifetime of P* becomes 4–5 times slower at cryogenic temperatures. From EPR and absorbance-detected magnetic resonance (ADMR, LD-ADMR) we conclude that the dimeric structure of P is not significantly changed upon mutation. In contrast, the interaction of the accessory bacteriochlorophyll BA with its environment appears to be altered, possibly because of a change in its position
Hardware-in-the-Loop Co-Simulation Based Validation of Power System Control Applications
Renewables are key enablers for the realization of a sustainable energy
supply but grid operators and energy utilities have to mange their intermittent
behavior and limited storage capabilities by ensuring the security of supply
and power quality. Advanced control approaches, automation concepts, and
communication technologies have the potential to address these challenges by
providing new intelligent solutions and products. However, the validation of
certain aspects of such smart grid systems, especially advanced control and
automation concepts is still a challenge. The main aim of this work therefore
is to introduce a hardware-in-the-loop co-simulation-based validation framework
which allows the simulation of large-scale power networks and control solutions
together with real-world components. The application of this concept to a
selected voltage control example shows its applicability.Comment: 2018 IEEE 27th International Symposium on Industrial Electronics
(ISIE
Specialist role coaching and skill training periodisation: A football goalkeeping case study
© The Author(s) 2020. In sports like association football, professional teams are increasingly devoting resources to the role-based development of individual athletes and sub-groups. By employing ‘specialist coaches’ into athlete-support structures, clubs aim to facilitate individualised athlete training programs to enhance performance preparation as well as skill learning and talent development. Here, we discuss how contemporary pedagogical training approaches, like Nonlinear Pedagogy and the Constraints-Led approach, can enhance effectiveness of specialist role-based athlete development programs to facilitate performance functionality. We argue the need for a model of specialist role-based coaching practice in high performance sports organisations, based on a unified theoretical rationale, such as ecological dynamics. To exemplify the nature of specialist role-based coaching, a case study addresses how Nonlinear Pedagogy and Constraints-Led approach are being used for training professional football goalkeepers in an U23 years age group. Integrating key concepts from ecological dynamics, allied to principles of Nonlinear Pedagogy and the Constraints-Led approach, common skill training principles for specialist role coaches are highlighted. These illustrate the use of the recently introduced ‘Periodization of Skill Training’ framework for specialist role coaching, practically exemplifying a way to harness opportunities for performance enhancement and individualised talent development in the football goalkeeping context
Explosive forming of 2219 aluminum final report
Variables affecting metal springback of aluminum during explosive deformation and influence of high energy forming on metallurgical behavio
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Chronic nicotine administration restores brain region specific upregulation of oxytocin receptor binding levels in a G72 mouse model of schizophrenia.
Nicotine dependence and schizophrenia are two mental health disorders with remarkably high comorbidity. Cigarette smoking is particularly prevalent among schizophrenic patients and it is hypothesized to comprise a form of self-medication for relieving cognitive deficits in these patients. Emerging evidence suggests a role of the neurohypophysial peptide oxytocin in the modulation of drug addiction, as well as schizophrenia symptomology; however, the underlying mechanism remains unclear. Therefore, we sought to investigate the effects of chronic nicotine administration on oxytocin receptor (OTR) binding in the brain of a transgenic mouse model of schizophrenia that carries a bacterial artificial chromosome of the human G72/G30 locus (G72Tg). Female wild-type (WT) and heterozygous G72 transgenic CD-1 mice were treated with a chronic nicotine regimen (24 mg/kg/day, osmotic minipumps for 14 days) and quantitative autoradiographic mapping of oxytocin receptors was carried out in brains of these animals. OTR binding levels were higher in the cingulate cortex (CgCx), nucleus accumbens (Acb) and central amygdala (CeA) of saline treated G72Tg mice compared with WT control mice. Chronic nicotine administration reversed this upregulation in the CgCx and CeA. Interestingly, chronic nicotine administration induced an increase in OTR binding in the CeA of solely WT mice. These results indicate that nicotine administration normalizes the dysregulated central oxytocinergic system of this mouse model of schizophrenia and may contribute towards nicotine's ability to modulate cognitive deficits which are common symptoms of schizophrenia. This article is protected by copyright. All rights reserved
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