892,865 research outputs found
Wegner estimate for discrete alloy-type models
We study discrete alloy-type random Schr\"odinger operators on
. Wegner estimates are bounds on the average number of
eigenvalues in an energy interval of finite box restrictions of these types of
operators. If the single site potential is compactly supported and the
distribution of the coupling constant is of bounded variation a Wegner estimate
holds. The bound is polynomial in the volume of the box and thus applicable as
an ingredient for a localisation proof via multiscale analysis.Comment: Accepted for publication in AHP. For an earlier version see
http://www.ma.utexas.edu/mp_arc-bin/mpa?yn=09-10
Localization of the SFT inspired Nonlocal Linear Models and Exact Solutions
A general class of gravitational models driven by a nonlocal scalar field
with a linear or quadratic potential is considered. We study the action with an
arbitrary analytic function , which has both simple and double roots.
The way of localization of nonlocal Einstein equations is generalized on models
with linear potentials. Exact solutions in the Friedmann-Robertson-Walker and
Bianchi I metrics are presented.Comment: 20 pages, 3 figures, published in the proceedings of the VIII
International Workshop "Supersymmetries and Quantum Symmetries" (SQS'09),
Dubna, Russia, July 29 - August 3, 2009, http://theor.jinr.ru/~sqs09
Pengaruh Modifikasi Latihan Double Leg Box Bound terhadap Explosive Power Otot Tungkai pada Siswa Kelas X SMA 12 Pekanbaru
Based on observations on a badminton player class X SMA 12 Pekanbaru, researchers found that the phenomenon of leg muscle explosive power in badminton player class X SMA 12 Pekanbaru still looks less than the maximum. The purpose of this research was to determine whether there are significant modifications to practice double-leg box bound to the explosive power leg muscle in Class X SMA 12 Pekanbaru. This study was an experimental study. In this study the authors took samples from the majority population in 12 high school students of class X MIPA Pekanbaru 4 male students as many as 14 people. The instrument of this study tests used are standing Broad Jump.Data tests analyzed using normality test and test hypotheses. Furthermore, to determine the extent of the Effect of Modification Exercises Double Leg Box Bound Against Explosive Power Muscles Legs In Class X SMA 12 Pekanbaru seen from t = 3,756, while table = 1,771 and this means that there Effect of Modification Exercises Double Leg Box Bound Against Explosive Power Limbs muscles In Class X SMA 12 Pekanbaru or Ho rejected and Ha accepted. Then, the results showed a significant difference to the upgrading of 12:09%
Observations of ozone production in a dissipating tropical convective cell during TC4
From 13 July–9 August 2007, 25 ozonesondes were launched from Las Tablas, Panama as part of the Tropical Composition, Cloud, and Climate Coupling (TC4) mission. On 5 August, a strong convective cell formed in the Gulf of Panama. World Wide Lightning Location Network (WWLLN) data indicated 563 flashes (09:00–17:00 UTC) in the Gulf. NO2 data from the Ozone Monitoring Instrument (OMI) show enhancements, suggesting lightning production of NOx. At 15:05 UTC, an ozonesonde ascended into the southern edge of the now dissipating convective cell as it moved west across the Azuero Peninsula. The balloon oscillated from 2.5–5.1 km five times (15:12–17:00 UTC), providing a unique examination of ozone (O3) photochemistry on the edge of a convective cell. Ozone increased at a rate of 1.6–4.6 ppbv/hr between the first and last ascent, resulting cell wide in an increase of (2.1–2.5)×106 moles of O3. This estimate agrees to within a factor of two of our estimates of photochemical lightning O3 production from the WWLLN flashes, from the radar-inferred lightning flash data, and from the OMI NO2 data (1.2, 1.0, and 1.7×106 moles, respectively), though all estimates have large uncertainties. Examination of DC-8 in situ and lidar O3 data gathered around the Gulf that day suggests 70–97% of the O3 change occurred in 2.5–5.1 km layer. A photochemical box model initialized with nearby TC4 aircraft trace gas data suggests these O3 production rates are possible with our present understanding of photochemistry
Quantum algorithms to solve the hidden shift problem for quadratics and for functions of large Gowers norm
Most quantum algorithms that give an exponential speedup over classical
algorithms exploit the Fourier transform in some way. In Shor's algorithm,
sampling from the quantum Fourier spectrum is used to discover periodicity of
the modular exponentiation function. In a generalization of this idea, quantum
Fourier sampling can be used to discover hidden subgroup structures of some
functions much more efficiently than it is possible classically. Another
problem for which the Fourier transform has been recruited successfully on a
quantum computer is the hidden shift problem. Quantum algorithms for hidden
shift problems usually have a slightly different flavor from hidden subgroup
algorithms, as they use the Fourier transform to perform a correlation with a
given reference function, instead of sampling from the Fourier spectrum
directly. In this paper we show that hidden shifts can be extracted efficiently
from Boolean functions that are quadratic forms. We also show how to identify
an unknown quadratic form on n variables using a linear number of queries, in
contrast to the classical case were this takes Theta(n^2) many queries to a
black box. What is more, we show that our quantum algorithm is robust in the
sense that it can also infer the shift if the function is close to a quadratic,
where we consider a Boolean function to be close to a quadratic if it has a
large Gowers U_3 norm.Comment: 12 pages, no figures, Proc. MFCS'09, LNCS vol. 5734, pp. 663-674,
2009. Mezzanine tranche of earlier paper arXiv:0811.320
Influence of frictions on gait optimization of a biped robot with an anthropomorphic knee
This paper presents the energy consumption of a biped robot with a new modelled structure of knees which is called rolling knee (RK). The dynamic model, the actuators and the friction coefficients of the gear box are known. The optimal energy consumption can also be calculated. The first part of the paper is to validate the new kinematic knee on a biped robot by comparing the energy consumption during a walking step of the identical biped but with revolute joint knees. The cyclic gait is given by a succession of Single Support Phase (SSP) followed by an impact. The gait trajectories are parameterized by cubic spline functions. The energetic criterion is minimized through optimization while using the simplex algorithm and Lagrange penalty functions to meet the constraints of stability and deflection of the mobile foot. An analysis of the friction coefficients is done by simulation to compare the human characteristics to the robot with RK. The simulation results show an energy consumption reduction through the biped with rolling knee configuration. The influence of friction coefficients shows the energy consumption of biped robot is close to that of the human.ANR-09-SEGI-011-R2A2; French National Research Agenc
Systems Biology Graphical Notation: Process Description language Level 1
Standard graphical representations have played a crucial role in science and engineering throughout the last century. Without electrical symbolism, it is very likely that our industrial society would not have evolved at the same pace. Similarly, specialised notations such as the Feynmann notation or the process flow diagrams did a lot for the adoption of concepts in their own fields. With the advent of Systems Biology, and more recently of Synthetic Biology, the need for precise and unambiguous descriptions of biochemical interactions has become more pressing. While some ideas have been advanced over the last decade, with a few detailed proposals, no actual community standard has emerged. The Systems Biology Graphical Notation (SBGN) is a graphical representation crafted over several years by a community of biochemists, modellers and computer scientists. Three orthogonal and complementary languages have been created, the Process Diagrams, the Entity Relationship Diagrams and the Activity Flow Diagrams. Using these three idioms a scientist can represent any network of biochemical interactions, which can then be interpreted in an unambiguous way. The set of symbols used is limited, and the grammar quite simple, to allow its usage in textbooks and its teaching directly in high schools. The first level of the SBGN Process Diagram has been publicly released. Software support for SBGN Process Diagram was developed concurrently with its specification in order to speed-up public adoption. Shared by the communities of biochemists, genomicians, theoreticians and computational biologists, SBGN languages will foster efficient storage, exchange and reuse of information on signalling pathways, metabolic networks and gene regulatory maps
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