807 research outputs found
Connectivity and Performance Tradeoffs in the Cascade Correlation Learning Architecture
The Cascade Correlation [1] is a very flexible, efficient and fast algorithm for supervised learning. It incrementally builds the network by adding hidden units one at a time, until the desired input/output mapping is achieved. It connects all the previously installed units to the new unit being added. Consequently, each new unit in effect adds a new layer and the fan–in of the hidden and output units keeps on increasing as more units get added. The resulting structure could be hard to implement in VLSI, because the connections are irregular and the fan-in is unbounded. Moreover, the depth or the propagation delay through the resulting network is directly proportional to the number of units and can be excessive. We have modified the algorithm to generate networks with restricted fan-in and small depth (propagation delay) by controlling the connectivity. Our results reveal that there is a tradeoff between connectivity and other performance attributes like depth, total number of independent parameters, learning time, etc. When the number of inputs or outputs is small relative to the size of the training set, a higher connectivity usually leads to faster learning, and fewer independent parameters, but it also results in unbounded fan-in and depth. Strictly layered architectures with restricted connectivity, on the other hand, need more epochs to learn and use more parameters, but generate more regular structures, with smaller, limited fan-in and significantly smaller depth (propagation delay), and may be better suited for VLSI implementations. When the number of inputs or outputs is not very small compared to the size of the training set, however, a strictly layered topology is seen to yield an overall better performance
Acceptance Dependence of Fluctuation in Particle Multiplicity
The effect of limiting the acceptance in rapidity on event-by-event
multiplicity fluctuations in nucleus-nucleus collisions has been investigated.
Our analysis shows that the multiplicity fluctuations decrease when the
rapidity acceptance is decreased. We explain this trend by assuming that the
probability distribution of the particles in the smaller acceptance window
follows binomial distribution. Following a simple statistical analysis we
conclude that the event-by-event multiplicity fluctuations for full acceptance
are likely to be larger than those observed in the experiments, since the
experiments usually have detectors with limited acceptance. We discuss the
application of our model to simulated data generated using VENUS, a widely used
event generator in heavy-ion collisions. We also discuss the results from our
calculations in presence of dynamical fluctuations and possible observation of
these in the actual data.Comment: To appear in Int. J. Mod. Phys.
Study of Behaviour of Square and Rectangular Footings Resting on Cohesive Soils Based on Model Tests
The estimation of a reliable value of bearing Capacity of soil is the most important step in the foundation design work. Number of theoretical approaches and in-situ tests for the estimation of bearing capacity of footing are available. The reliability of any theory can be demonstrated by comparing the experimental test results on field footings with theoretical predictions. One of the reliable methods is the load test on full sized footing. However, this test as covered under IS 1888-1982 is too expensive and time consuming. Model tests can be conducted on footings of various sizes. The surface characteristics for different loading conditions can provide information on qualitative and quantitative contribution of such parameters on bearing of footings in absence of field test results. It is revealed that research work (Sawant et al (2000), Rajgopal et al (2000), Sawaf et al (2005), Mohmoud et al (1989), Harikrishna et al(2000), Sahu et al (1970) etc.)has been carried out for load tests on model footings resting on sand as foundation medium. However no work has been reported so far on c – Φ soil. In this present study a laboratory model with loading frame has been developed in Geotechnical Engineering Laboratory of College of Engineering, Pune to conduct small scale load tests, to determine Bearing capacity characteristics of footings resting on c-Φ soil. Load tests were conducted on two square, two circular and five rectangular footings resting on c – Φ soil in the laboratory model. The bearing capacity, time – settlement relationship, pressure settlement relationship of footing resting on c – Φ soil and effect of various parameters such as L/B ratio, shape and size of footing on bearing capacity of footing were studied. Comparison is made between bearing capacity of footings estimated by the conventional methods such as Vesic’s, Tezaghi’s method and that estimated by Model Test Results. The model tests provide qualitative information on parameters influencing bearing capacity of footings. These tests can be used to check the bearing capacity estimated by analytical method
Estimation of Phreatic Line Using Dimensional Analysis
A new technique using dimensional analysis (D.A.) is presented here to draw profile of phreatic line through an earthen dam. A universal equation is formulated using D.A. to get numerous points on a steady-state phreatic surface. The prediction of phreatic line using D.A. is then compared with those of conventional methods by Kozeny, A. Casagrande, Stello and also with centrifuge model test results and large scale prototype field results to evaluate applicability of this equation. It has been observed that D.A. can predict the results reasonably well. Thus Dimensional Analysis method can prove to be an easy and sufficiently accurate method to predict solutions to complex and multiparameter problems
EFFECT OF MURRAYA KOENIGII LEAVES EXTRACT ON GLUCONEOGENESIS AND GLYCOGENOLYSIS IN ISOLATED RAT HEPATOCYTES CULTURE
Objectives: The present study was aimed to investigate the in vitro activity of Murraya koenigii extracts through various carbohydrate metabolic pathways in the isolated rat hepatocyte models.Methods: Different doses of metformin, aqueous and methanol extracts of M. koenigii leaves were evaluated in the MTT, glucose, and glycogen content assays in the cultured in vitro rat hepatocytes.Results: The study showed that there was a significant increase in activity with respect to the increased concentration of extracts. Slight effect was observed in the isolated rat hepatocytes culture, M. koenigii leaves extract may exert cytoprotective and hypoglycemic action.Conclusion: It may be needed to determine the effect of ex vivo rat hepatocytes isolated from diabetic rats. Effects of the plant or isolated compounds on the genes expression of signaling pathways should be investigated in further studies
Meson-Baryon Form Factors in Chiral Colour Dielectric Model
The renormalised form factors for pseudoscalar meson-baryon coupling are
computed in chiral colour dielectric model. This has been done by rearranging
the Lippmann-Schwinger series for the meson baryon scattering matrix so that it
can be expressed as a baryon pole term with renormalized form factors and
baryon masses and the rest of the terms which arise from the crossed diagrams.
Thus we are able to obtain an integral equation for the renormalized
meson-baryon form factors in terms of the bare form factors as well as an
expression for the meson self energy. This integral equation is solved and
renormalized meson baryon form factors and renormalized baryon masses are
computed. The parameters of the model are adjusted to obtain a best fit to the
physical baryon masses. The calculations show that the renormalized form
factors are energy-dependent and differ from the bare form factors primarily at
momentum transfers smaller than 1 GeV. At nucleon mass, the change in the form
factors is about 10% at zero momentum transfer. The computed form factors are
soft with the equivalent monopole cut-off mass of about 500 MeV. The
renormalized coupling constants are obtained by comparing the chiral colour
dielectric model interaction Hamiltonian with the standard form of
meson-nucleon interaction Hamiltonian. The ratio of and
coupling constants is found to be about 2.15. This value is very close to the
experimental value.Comment: 16 pages, 7 postscript figure
Dihyperon in Chiral Colour Dielectric Model
The mass of dihyperon with spin, parity and isospin
is calculated in the framework of Chiral colour dielectric model. The wave
function of the dihyperon is expressed as a product of two colour-singlet
baryon clusters. Thus the quark wave functions within the cluster are
antisymmetric. Appropriate operators are then used to antisymmetrize
inter-cluster quark wave functions. The radial part of the quark wavefunctions
are obtained by solving the the quark and dielectric field equations of motion
obtained in the Colour dielectric model. The mass of the dihyperon is computed
by including the colour magnetic energy as well as the energy due to meson
interaction. The recoil correction to the dihyperon mass is incorporated by
Peierls-Yoccoz technique. We find that the mass of the dihyperon is smaller
than the threshold by over 100 MeV. The implications of our
results on the present day relativistic heavy ion experiments is discussed.Comment: LaTeX, 13 page
Three flavour Quark matter in chiral colour dielectric model
We investigate the properties of quark matter at finite density and
temperature using the nonlinear chiral extension of Colour Dielectric Model
(CCM). Assuming that the square of the meson fields devlop non- zero vacuum
expectation value, the thermodynamic potential for interacting three flavour
matter has been calculated. It is found that remain zero
in the medium whereas changes in the medium. As a result, and
quark masses decrease monotonically as the temperature and density of the quark
matter is increased.In the present model, the deconfinement density and
temperature is found to be lower compared to lattice results. We also study the
behaviour of pressure and energy density above critical temperature.Comment: Latex file. 5 figures available on request. To appear in Phys. Rev.
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