4,649 research outputs found
Aggregation procedure based on majority principle for collective identification of firm’s crucial knowledge
It is very important to identify, preserve, and transfer knowledge to those who need it within firm. However, the identification of knowledge and especially tacit knowledge is a complex process because knowledge cannot be measured quantitatively. In this paper we present an approach for inducing a set of collective decision rules representing a generalized description of the preferential information of a group of decision makers involved in a multicriteria classification problem to identify crucial knowledge to be capitalized
On Calculus of Manifolds with Special Emphasis of 3D Minkowski Space M2,1
In this paper, we explain some topics of calculus of manifold, especially for the spacetime symmetry topic. With emphasis of 3D Minkowski differential geometry. The most important symmetries are nbsp, A diffeomorphism of this symmetry is called the isometry. If a one-parameter group of isometries is generated by a vector field, then quotthis vector field is called a Killing vector field. Which shows that the Lei derivative is vanishingquot [14]. Moreover the one parameter group of diffeomorphism called the flow. However the Poincare#39 group quotis the group of isometries of Minkowski spacetime. Also quotit is a full symmetry of special relativity includes the translations , rotation and boostsquot [11]
Nonequilibrium electron transport using the density matrix renormalization group
We extended the Density Matrix Renormalization Group method to study the real
time dynamics of interacting one dimensional spinless Fermi systems by applying
the full time evolution operator to an initial state. As an example we describe
the propagation of a density excitation in an interacting clean system and the
transport through an interacting nano structure
Eigenvalue bounds for a class of singular potentials in N dimensions
The eigenvalue bounds obtained earlier [J. Phys. A: Math. Gen. 31 (1998) 963]
for smooth transformations of the form V(x) = g(x^2) + f(1/x^2) are extended to
N-dimensions. In particular a simple formula is derived which bounds the
eigenvalues for the spiked harmonic oscillator potential V(x) = x^2 +
lambda/x^alpha, alpha > 0, lambda > 0, and is valid for all discrete
eigenvalues, arbitrary angular momentum ell, and spatial dimension N.Comment: 10 pages (plain tex with 2 ps figures). J.Phys.A:Math.Gen.(In Press
Solvable Systems of Linear Differential Equations
The asymptotic iteration method (AIM) is an iterative technique used to find
exact and approximate solutions to second-order linear differential equations.
In this work, we employed AIM to solve systems of two first-order linear
differential equations. The termination criteria of AIM will be re-examined and
the whole theory is re-worked in order to fit this new application. As a result
of our investigation, an interesting connection between the solution of linear
systems and the solution of Riccati equations is established. Further, new
classes of exactly solvable systems of linear differential equations with
variable coefficients are obtained. The method discussed allow to construct
many solvable classes through a simple procedure.Comment: 13 page
Effective photon mass and exact translating quantum relativistic structures
Using a variation of the celebrated Volkov solution, the Klein-Gordon
equation for a charged particle is reduced to a set of ordinary differential
equations, exactly solvable in specific cases. The new quantum relativistic
structures can reveal a localization in the radial direction perpendicular to
the wave packet propagation, thanks to a non-vanishing scalar potential. The
external electromagnetic field, the particle current density and the charge
density are determined. The stability analysis of the solutions is performed by
means of numerical simulations. The results are useful for the description of a
charged quantum test particle in the relativistic regime, provided spin effects
are not decisive
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