91,805 research outputs found
Solusi-solusi Periodik Pada Perluasan Fractional Van-der Pol Tak Linear
In this paper will be studied a Generalized Non Linear Rayleigh Oscillator. It will be shown that the recently developed perturbation method based on integrating factors can be used to approximate first integrals and periodic solutions. Not only approximations of first integrals will be given, but it will also be shown how in a rather efficient way the existence and stability of time-periodic solutions can be obtained from these approximations
How to understand the cell by breaking it: network analysis of gene perturbation screens
Modern high-throughput gene perturbation screens are key technologies at the
forefront of genetic research. Combined with rich phenotypic descriptors they
enable researchers to observe detailed cellular reactions to experimental
perturbations on a genome-wide scale. This review surveys the current
state-of-the-art in analyzing perturbation screens from a network point of
view. We describe approaches to make the step from the parts list to the wiring
diagram by using phenotypes for network inference and integrating them with
complementary data sources. The first part of the review describes methods to
analyze one- or low-dimensional phenotypes like viability or reporter activity;
the second part concentrates on high-dimensional phenotypes showing global
changes in cell morphology, transcriptome or proteome.Comment: Review based on ISMB 2009 tutorial; after two rounds of revisio
Performance optimization of a leagility inspired supply chain model: a CFGTSA algorithm based approach
Lean and agile principles have attracted considerable interest in the past few decades. Industrial sectors throughout the world are upgrading to these principles to enhance their performance, since they have been proven to be efficient in handling supply chains. However, the present market trend demands a more robust strategy incorporating the salient features of both lean and agile principles. Inspired by these, the leagility principle has emerged, encapsulating both lean and agile features. The present work proposes a leagile supply chain based model for manufacturing industries. The paper emphasizes the various aspects of leagile supply chain modeling and implementation and proposes a new Hybrid Chaos-based Fast Genetic Tabu Simulated Annealing (CFGTSA) algorithm to solve the complex scheduling problem prevailing in the leagile environment. The proposed CFGTSA algorithm is compared with the GA, SA, TS and Hybrid Tabu SA algorithms to demonstrate its efficacy in handling complex scheduling problems
Non-linear matter power spectrum from Time Renormalisation Group: efficient computation and comparison with one-loop
We address the issue of computing the non-linear matter power spectrum on
mildly non-linear scales with efficient semi-analytic methods. We implemented
M. Pietroni's Time Renormalization Group (TRG) method and its Dynamical 1-Loop
(D1L) limit in a numerical module for the new Boltzmann code CLASS. Our
publicly released module is valid for LCDM models, and optimized in such a way
to run in less than a minute for D1L, or in one hour (divided by number of
nodes) for TRG. A careful comparison of the D1L, TRG and Standard 1-Loop
approaches reveals that results depend crucially on the assumed initial
bispectrum at high redshift. When starting from a common assumption, the three
methods give roughly the same results, showing that the partial resumation of
diagrams beyond one loop in the TRG method improves one-loop results by a
negligible amount. A comparison with highly accurate simulations by M. Sato &
T. Matsubara shows that all three methods tend to over-predict non-linear
corrections by the same amount on small wavelengths. Percent precision is
achieved until k~0.2 h/Mpc for z>2, or until k~0.14 h/Mpc at z=1.Comment: 24 pages, 7 figures, revised title and conclusions, version accepted
in JCAP, code available at http://class-code.ne
Field Theoretic Description of Ultrarelativistic Electron-Positron Plasmas
Ultrarelativistic electron-positron plasmas can be produced in high-intensity
laser fields and play a role in various astrophysical situations. Their
properties can be calculated using QED at finite temperature. Here we will use
perturbative QED at finite temperature for calculating various important
properties, such as the equation of state, dispersion relations of collective
plasma modes of photons and electrons, Debye screening, damping rates, mean
free paths, collision times, transport coefficients, and particle production
rates, of ultrarelativistic electron-positron plasmas. In particular, we will
focus on electron-positron plasmas produced with ultra-strong lasers.Comment: 13 pages, 7 figures, 1 table, published versio
Field Theory On the World Sheet: Mean Field Expansion And Cutoff Dependence
Continuing earlier work, we apply the mean field method to the world sheet
representation of a simple field theory. In particular, we study the higher
order terms in the mean field expansion, and show that their cutoff dependence
can be absorbed into a running coupling constant. The coupling constant runs
towards zero in the infrared, and the model tends towards a free string. One
cannot fully reach this limit because of infrared problems, however, one can
still apply the mean field method to the high energy limit (high mass states)
of the string.Comment: 29 Pages, 3 Figure
New nonlocal effective action
We suggest a new method for the calculation of the nonlocal part of the
effective action. It is based on resummation of perturbation series for the
heat kernel and its functional trace at large values of the proper time
parameter. We derive a new, essentially nonperturbative, nonlocal contribution
to the effective action in spacetimes with dimensions .Comment: 28 pages, latex, no figures, typos are corrected, presentation
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