Download Buletin Stiintific - UPB - Seria A - numar 3 - 2009

U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
Contents
MATHEMATICS
Mariana Craiu
Parametric estimation of conditional copulas
Mariana Dumitru
Gamma-Ring: some interpretations used in the study of their radicals
3
9
Carmina Georgescu
Random solutions of functional differential inclusions of neutral type
23
Ştefania Constantinescu
Some applications of the hilbert transform
35
Adriana Balan
Yetter-Drinfeld modules and Galois extensions over coquasi-Hopf algebras
43
Ariana Pitea
On efficiency conditions for new constrained minimum problem
61
Feng Qi, Anthony Sofo
An alternative and united proof of a double inequality for bounding the
arithmetic-geometric mean
69
PHYSICS
Constantin P. Cristescu, Marcel Popescu
Entangled quantum states, quantum teleportation and quantum information
77
Alexandru Lupaşcu
Relativistic results obtained by classical arguments
95
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
Elfrida M. Carstea, Gabriela Pavelescu, Luminita Cristescu, Andy Baker, Dan
Savastru
Comparison between the characteristics of dissolved organic matter and
nitrate content in an urban river
105
Ligia Strasser, Gheorghe Căta-Danil
Heavy ions straggling in biological matter
111
Sorin Ghinoiu, Niculae N. Puşcaş
The metrology of optical fibre losses
121
Liviu Andronovici
Study of the solidification process for metal fluids in a dynamic field
129
Mircea Stan
Reversibility and irreversibility in physical systems
143
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
PARAMETRIC ESTIMATION OF CONDITIONAL COPULAS
Mariana CRAIU
Copulas have evolved into a popular tool for modeling
dependence in a large number of statistical models.Generally, a
copula establishes a flexible bridge between marginal distributions
,thus allowing various dependent models to be created.Recently ,an
extension of the classical copula construction allows us to incorporate
covariates in the model and allows the copula parameter to vary with
some of these covariates. In this paper I investigate inference using
linear models for conditional copula parameters.
Keywords: Copulas, Conditional Copulas,Clayton Copula,Frank Copula, linear
models.
Mathematics Subject Classification 2000:62H12,62E20
GAMMA-RINGS: SOME INTERPRETATIONS USED IN THE
STUDY OF THEIR RADICALS
Mariana DUMITRU
We study some concepts of gamma-rings and ternary rings,
inspired by the study of rectangular matrices over fields. We point
out some of their properties which are necessary for defining radicals
for such algebraic structures and getting structure theorems. Some
connections between maximal ideals in the gamma-rings and those in
the associated rings.
Keywords: Gamma-rings; modules; radicals.
MSC 2000: 16Y99
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
RANDOM SOLUTIONS OF FUNCTIONAL DIFFERENTIAL
INCLUSIONS OF NEUTRAL TYPE
Carmina GEORGESCU
This paper is devoted to the study of neutral functional
differential inclusions defined on a separable Banach space and
depending in a measurable way on a random parameter. We first
prove an existence result for a class of neutral functional differential
inclusions with memory. Then we establish a condition under which
the existence of viable solutions yields the existence of random viable
solutions to neutral functional differential inclusions.
Keywords: functional-differential inclusions with memory, random inclusions,
viable solutions, measurable selections.
2000 Mathematics Subject Classification: 34A60, 34K40, 34F05.
SOME APPLICATIONS OF THE HILBERT TRANSFORM
Ştefania Constantinescu
In this paper we recall some properties of the Hilbert transform
interpreted in terms of the mathematical theory of the random signals.
We study the representation of the analitical signals as a
generalization of the complex form of the sinusoidal signals, a special
part being focused on the spectral properties, in connection with the
concept of power density. It is also presented an example taken from
practice of the electronic circuits.
Keywords: Fourier transform, Hilbert transform, analytical representation
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
YETTER-DRINFELD MODULES AND GALOIS EXTENSIONS
OVER COQUASI-HOPF ALGEBRAS
Adriana BALAN
In this paper we define Yetter-Drinfeld modules over a
coquasi-bialgebra and prove that the category of Yetter.Drinfeld
modules is monoidal, pre.braided and coincides with the left weak
center of the comodule category. In particular, given a Galois
extension B ⊆ A over a coquasi-Hopf algebra, the centralizer AB is a
commutative algebra in the braided category YD HH and the center of
the category of Hopf (H,A)-bimodules is equivalent to the category of
Yetter-Drinfeld modules, generalizing the results obtained by
Schauenburg in the Hopf algebra case.
Keywords: Coquasi-Hopf algebra, monoidal category, Yetter-Drinfeld module,
Galois extension.
ON EFFICIENCY CONDITIONS FOR NEW CONSTRAINED
MINIMUM PROBLEM
Ariana Pitea
Consider the problem (MP) of minimizing a vector of
functionals of curvilinear integrals subject to PDE and/or PDI
constraints. In two previous papers [5], [6], we studied efficiency
necessary conditions for the problem (MP) and we introduced a new
type of duality. The aim of this work is to introduce and study
sufficient conditions for the efficiency of a feasible solution of the
problem (MP). The results discussed in §2 are new.
Keywords: Efficient solution, PDE, PDI, normal efficient solution.
MSC2000: primary 49J40, 49K20; secondary 58E17, 65K10, 53C65
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
AN ALTERNATIVE AND UNITED PROOF OF A DOUBLE
INEQUALITY FOR BOUNDING THE ARITHMETICGEOMETRIC MEAN
Feng Qi, Anthony Sofo
In the paper, we provide an alternative and united proof of a double
inequality for bounding the arithmetic-geometric mean. Moreover we prove that
the bounding constants of the double inequality are the best possible.
Keywords: alternative and united proof, double inequality, arithmetic-geometric
mean, complete elliptic integral of the first kind, generalized
logarithmic mean
MSC2000: primary 33C75, 33E05; secondary 26D15
ENTANGLED QUANTUM STATES, QUANTUM
TELEPORTATION AND QUANTUM INFORMATION
Constantin P. Cristescu, Marcel Popescu
The paper presents the essentials concerning the quantum
entangled states as a fundamental resource for quantum informatics.
The treatment roughly follows the debate of over 70 years generated
by the Einstein, Podolsky, Rosen paper formulating what was later
called “the EPR paradox”, and presents the celebrated experiments
that settled the debate. Recent experiments on the application of
entangled states such as quantum teleportation and its relevance for
quantum communications are discussed.
Keywords: entangled states, epr paradox, bell inequalities, quantum
teleportation
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
RELATIVISTIC RESULTS OBTAINED BY CLASSICAL
ARGUMENTS
Alexandru LUPAŞCU
We present the problem of reflection at a moving surface and
show that relativistic results may be deduced from simple nonrelativistic computations. The variations of the frequency of the
reflected wave and of the reflected angle are studied as functions of
the incident angle and of the velocity of the surface. In the same
framework we discuss relativistic Doppler effect.
Keywords: reflection at a moving boundary, Special relativity, non-relativistic
computations
COMPARISON BETWEEN THE CHARACTERISTICS OF
DISSOLVED ORGANIC MATTER AND NITRATE CONTENT
IN AN URBAN RIVER
Elfrida M. CARSTEA, Gabriela PAVELESCU, Luminita CRISTESCU,
Andy BAKER, Dan SAVASTRU
Aquatic organic matter is constantly changing its
characteristics under the interaction with different components which
enter the water body through soil leaching, surface runoff or
pollution. Complex processes also lead to the formation of nitrate. In
order to determine the quantity of nitrate and the correlation with
dissolved organic matter a continuous monitoring experiment of an
urban river has been performed. This study has been conducted by
measuring the fluorescence of organic matter and physiochemical
parameters. Surface runoff had a great impact on the river water
quality triggering after each precipitation event high quantities of
nitrate and organic matter.
Keywords: dissolved organic matter, fluorescence spectroscopy, nitrate, urban
river.
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
HEAVY IONS STRAGGLING IN BIOLOGICAL MATTER
Ligia STRASSER, Gheorghe CATA-DANIL
In the present work it is performed a systematic study of the
lateral and longitudinal stragglings occuring in the slowing down of
12
C, 16O and 19F ions in materials of interest for radiotherapy. The
incident energy of the ion beams considered in the present work were
selected in order to ensure in liquid water 19,1 mm range. Liquid
water is used as a benchmark for evaluation of the lateral and
longitudinal stragglings. To approach more realistic cases the study
was extended to muscle and bone. The specific stragglings have been
evaluated for each type of ion beam and target. The entire approach
employed Monte Carlo numerical simulations based on the SRIM
software package.
Keywords: heavy ion straggling, bragg peak, Monte Carlo simulation
THE METROLOGY OF OPTICAL FIBRE LOSSES
Sorin GHINOIU, Niculae N. PUŞCAŞ
Based on the measurement of the propagation losses, optical
insertion and return losses of optical fibers using nondestructive methods
several experimental results are presented and analysed from metrology
point of view in this paper.
Using the Optical Transmission Method the attenuation of the
optical power corresponding to an optical signal launched into the fiber
was measured at λ =0.63 μ m with a bandwidth Δλ =0.03 μ m. Also, using
the Two Point Method we measured the attenuation of a single optical fibre
having 28964 m for a 1 μ s laser pulse having λ =1.55 μ m. Based on an
original set-up the optical insertion and return losses of optical fibers were
measured for λ =1.55 μ m. In the case of the propagation losses for
λ =1.55 μ m we performed an error calculation.
Keywords: metrology, optical fiber losses, optical attenuation, optical insertion
and return losses, nondestructive methods.
U.P.B. Sci. Bull., Series A, Vol. 71, Iss. 3, 2009
ISSN 1223-7027
STUDY OF THE SOLIDIFICATION PROCESS FOR METAL
FLUIDS IN A DYNAMIC FIELD
Liviu Andronovici
The this study presents the posibility of new technique applied to
fluid metals and their crystalline structure under the effect of the
energetic field of the pyramid.
there are two significant methods used to demonstrate the existence of the
pyramid’s energetic field: 1-measurement techniques using diferent devices that
demonstrate the existing waves inside the pyramid; 2-modification of crystalline
structure by casting several samples inside the pyramid. the experiments were
made on 4 metals, inside and outside the pyramid to obtain models for further
comparison.
REVERSIBILITY AND IRREVERSIBILITY IN PHYSICAL
SYSTEMS
Mircea STAN
This paper deals with a systematic approach to the study of
temporal reversibility and irreversibility in physical systems. Using a
simple formalism, several physical quantities and kinetic laws are
then checked in some domains (classical and quantum mechanics,
electrodynamics, et al.) through this point of view.
Keywords: reversibility, irreversibility, time - reversal operator, symmetrical and
anti-symmetrical quantity