411 research outputs found
Perspectives for Monte Carlo simulations on the CNN Universal Machine
Possibilities for performing stochastic simulations on the analog and fully
parallelized Cellular Neural Network Universal Machine (CNN-UM) are
investigated. By using a chaotic cellular automaton perturbed with the natural
noise of the CNN-UM chip, a realistic binary random number generator is built.
As a specific example for Monte Carlo type simulations, we use this random
number generator and a CNN template to study the classical site-percolation
problem on the ACE16K chip. The study reveals that the analog and parallel
architecture of the CNN-UM is very appropriate for stochastic simulations on
lattice models. The natural trend for increasing the number of cells and local
memories on the CNN-UM chip will definitely favor in the near future the CNN-UM
architecture for such problems.Comment: 14 pages, 6 figure
Numerical Study of Natural Convection in Square Tilted Solar Cavity Considering Extended Domain
Evidences of a consolute critical point in the Phase Separation regime of La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single crystals
We report on DC and pulsed electric field sensitivity of the resistance of
mixed valent Mn oxide based La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single
crystals as a function of temperature. The low temperature regime of the
resistivity is highly current and voltage dependent. An irreversible transition
from high (HR) to a low resistivity (LR) is obtained upon the increase of the
electric field up to a temperature dependent critical value (V_c). The
current-voltage characteristics in the LR regime as well as the lack of a
variation in the magnetization response when V_c is reached indicate the
formation of a non-single connected filamentary conducting path. The
temperature dependence of V_c indicates the existence of a consolute point
where the conducting and insulating phases produce a critical behavior as a
consequence of their separation.Comment: 5 pages, 6 figures, corresponding author: C. Acha ([email protected]
Uncertainty assessment for measurement processes in the aerospace manufacturing industry
Measurement processes are critical to the aerospace industry, which products must follow strict regulations and customer requirements. Additionally, measurement of uncertainty is fast becoming a requirement from both certification bodies and customers. An uncertainty assessment must be carried out for all processes that need to add an uncertainty statement to the measurement result. In order to maintain defined quality standards, aerospace manufacturing companies need to identify all measurement disciplines that benefit from stating the level of uncertainty and define a methodology to calculate it for complex measurement processes.
An extensive research has been conducted in order to define the most appropriate methodology to assess uncertainty on complex aerospace components and a case study has been applied to assess the strain gauge calibration test uncertainty of different aerospace components.
This study develops a generic framework, which helps the assessment of all individual sources of uncertainty and completes the one established by the Guide to the Expression of Uncertainty in Measurement. Conclusions have been extracted from the outcome of the case study.
The conducted research contributes to a better understanding of measurement processes and good practices that lead to lower uncertainty. The outcome will help manufacturing companies to be aware of the contributors of uncertainty to the tests, how to reduce this uncertainty and the reliability of the measurements taken during the process
DESIGN OF NEWMODEL FOR SLR-PARSER
: In last decades the applications of the computerized system were widely used in various environments, such real time systems, monitoring system and other. These applications need live answer from the programmable system. The compiler phases represent the heart of any programming language, therefore if we enhance the compilers; we make the execution more efficient.In this paper we present new model for SLR-Parser, which is the main stage of the compiler phases, because it responsible for the grammatical checking of the program statements and it needs more time than other stages. The new model appears faster than original parse. Also it is less complexity than original parser. Therefore, it is more efficient to use
RESPONSE OF NIGELLA SATIVA L. GROWTH AND OIL YIELD TO FOLIAR APPLICATION OF DRY YEAST, SALICYLIC ACID AND ASCORBIC ACID
This study was carried out to evaluate the effects of dry yeast (0.4 and 0.8%), salicylic acid (150 and 300 ppm) and ascorbic acid (150 and 300 ppm) as a spray application on black cumin plants to determine their effects on plant height, number of branches/plant, stem diameter, root length, capsule number/plant, capsules weight/plant, seed weights/plant, seed yield/fed, fixed oil percentage and oil yield/fed during both seasons. The highest concentration of each substance showed superiority in comparison with the lowest concentration of the same substance and the control. Salicylic acid at rate of 300 ppm showed significant increase in plant height, seed weight, seed yield and fixed oil yield. Meanwhile, Ascorbic acid at rate of 300 ppm presented significant increment in number of branches/plant, capsules number/plant, capsules weight and oil percentage. Dry yeast at rate 0.8% caused an increase in the root length which calculated at the first season as 17.15 cm and at the second season as 16.45 cm
Directed Percolation with a Wall or Edge
We examine the effects of introducing a wall or edge into a directed
percolation process. Scaling ansatzes are presented for the density and
survival probability of a cluster in these geometries, and we make the
connection to surface critical phenomena and field theory. The results of
previous numerical work for a wall can thus be interpreted in terms of surface
exponents satisfying scaling relations generalising those for ordinary directed
percolation. New exponents for edge directed percolation are also introduced.
They are calculated in mean-field theory and measured numerically in 2+1
dimensions.Comment: 14 pages, submitted to J. Phys.
Stochastic Light-Cone CTMRG: a new DMRG approach to stochastic models
We develop a new variant of the recently introduced stochastic
transfer-matrix DMRG which we call stochastic light-cone corner-transfer-matrix
DMRG (LCTMRG). It is a numerical method to compute dynamic properties of
one-dimensional stochastic processes. As suggested by its name, the LCTMRG is a
modification of the corner-transfer-matrix DMRG (CTMRG), adjusted by an
additional causality argument. As an example, two reaction-diffusion models,
the diffusion-annihilation process and the branch-fusion process, are studied
and compared to exact data and Monte-Carlo simulations to estimate the
capability and accuracy of the new method. The number of possible Trotter steps
of more than 10^5 shows a considerable improvement to the old stochastic TMRG
algorithm.Comment: 15 pages, uses IOP styl
A New Exponent Characterizing the Effect of Evaporation on Imbibition Experiments
We report imbibition experiments investigating the effect of evaporation on
the interface roughness and mean interface height. We observe a new exponent
characterizing the scaling of the saturated surface width. Further, we argue
that evaporation can be usefully modeled by introducing a gradient in the
strength of the disorder, in analogy with the gradient percolation model of
Sapoval {\it et~al.}. By incorporating this gradient we predict a new critical
exponent and a novel scaling relation for the interface width. Both the
exponent value and the form of the scaling agree with the experimental results.Comment: 12 pages, REVTeX 3.0, figures on request (accepted for PRL
Solutions for correlations along the coexistence curve and at the critical point of a kagom\'e lattice gas with three-particle interactions
We consider a two-dimensional (d=2) kagom\'e lattice gas model with
attractive three-particle interactions around each triangular face of the
kagom\'e lattice. Exact solutions are obtained for multiparticle correlations
along the liquid and vapor branches of the coexistence curve and at
criticality. The correlation solutions are also determined along the
continuation of the curvilinear diameter of the coexistence region into the
disordered fluid region. The method generates a linear algebraic system of
correlation identities with coefficients dependent only upon the interaction
parameter. Using a priori knowledge of pertinent solutions for the density and
elementary triplet correlation, one finds a closed and linearly independent set
of correlation identities defined upon a spatially compact nine-site cluster of
the kagom\'e lattice. Resulting exact solution curves of the correlations are
plotted and discussed as functions of the temperature, and are compared with
corresponding results in a traditional kagom\'e lattice gas having
nearest-neighbor pair interactions. An example of application for the
multiparticle correlations is demonstrated in cavitation theory
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