Abstract: Recent research result has shown that two multidelay
feedback systems can synchronize each other under different
schemes, i.e. lag, projective-lag, anticipating, or projectiveanticipating
synchronization. There, the driving signal is significantly
complex due that it is constituted by multiple nonlinear transformations
of delayed state variable. In this paper, a secure communication
model is proposed based on synchronization of coupled multidelay
feedback systems, in which the plain signal is mixed with a complex
signal at the transmitter side and it is precisely retrieved at the receiver
side. The effectiveness of the proposed model is demonstrated and
verified in the specific example, where the message signal is masked
directly by the complex signal and security is examined under the
breaking method of power spectrum analysis.
Abstract: In this paper we developed the Improved Runge-Kutta Nystrom (IRKN) method for solving second order ordinary differential equations. The methods are two step in nature and require lower number of function evaluations per step compared with the existing Runge-Kutta Nystrom (RKN) methods. Therefore, the methods are computationally more efficient at achieving the higher order of local accuracy. Algebraic order conditions of the method are obtained and the third and fourth order method are derived with two and three stages respectively. The numerical results are given to illustrate the efficiency of the proposed method compared to the existing RKN methods.
Abstract: The wave function at the origin is an important quantity in studying many physical problems concerning heavy quarkonia. This is because that it is using for calculating spin state hyperfine splitting and also crucial to evaluating the production and decay amplitude of the heavy quarkonium. In this paper, we present the variational method by using the single-parameter wave function to estimate the WFO for the ground state of heavy mesons.
Abstract: The interdependences among stock market indices
were studied for a long while by academics in the entire world. The
current financial crisis opened the door to a wide range of opinions
concerning the understanding and measurement of the connections
considered to provide the controversial phenomenon of market
integration. Using data on the log-returns of 17 stock market indices
that include most of the CEE markets, from 2005 until 2009, our
paper studies the problem of these dependences using a new
methodological tool that takes into account both the volatility
clustering effect and the stochastic properties of these linkages
through a Dynamic Conditional System of Simultaneous Equations.
We find that the crisis is well captured by our model as it provides
evidence for the high volatility – high dependence effect.
Abstract: The density estimates considered in this paper comprise
a base density and an adjustment component consisting of a linear
combination of orthogonal polynomials. It is shown that, in the
context of density approximation, the coefficients of the linear combination
can be determined either from a moment-matching technique
or a weighted least-squares approach. A kernel representation of
the corresponding density estimates is obtained. Additionally, two
refinements of the Kronmal-Tarter stopping criterion are proposed
for determining the degree of the polynomial adjustment. By way of
illustration, the density estimation methodology advocated herein is
applied to two data sets.
Abstract: Equilibrium and rate based models have been applied
in the simulation of methyl tertiary-butyl ether (MTBE) synthesis
through reactive distillation. Temperature and composition profiles
were compared for both the models and found that both the profiles
trends, though qualitatively similar are significantly different
quantitatively. In the rate based method (RBM), multicomponent
mass transfer coefficients have been incorporated to describe
interphase mass transfer. MTBE mole fraction in the bottom stream is
found to be 0.9914 in the Equilibrium Model (EQM) and only 0.9904
for RBM when the same column configuration was preserved. The
individual tray efficiencies were incorporated in the EQM and
simulations were carried out. Dynamic simulation have been also
carried out for the two column configurations and compared.
Abstract: In this paper, we consider the uniform asymptotic stability, global asymptotic stability and global exponential stability of the equilibrium point of discrete Hopfield neural networks with delays. Some new stability criteria for system are derived by using the Lyapunov functional method and the linear matrix inequality approach, for estimating the upper bound of Lyapunov functional derivative.
Abstract: Simulation and modeling computer programs are
concerned with construction of models for analyzing different
perspectives and possibilities in changing conditions environment.
The paper presents theoretical justification and evaluation of
qualitative e-learning development model in perspective of advancing
modern technologies. There have been analyzed principles of
qualitative e-learning in higher education, productivity of studying
process using modern technologies, different kind of methods and
future perspectives of e-learning in formal education. Theoretically
grounded and practically tested model of developing e-learning
methods using different technologies for different type of classroom,
which can be used in professor-s decision making process to choose
the most effective e-learning methods has been worked out.
Abstract: In conducting a case study to analyze the status-quo of
the extremists’ dominance in Egypt, the author of this paper uses
qualitative research method to analyze the evolution of extreme
Islamist groups in Egypt. In conducting this qualitative research, the
author of this paper intends to use several lenses to understand the
rise and the evolution of the hegemony of extremist groups, such as
the Muslim Brotherhood and other groups in Egypt. Therefore, unless
he intends to show an important nexus between the Egyptian groups
and their sister-groups in other countries, he will intentionally
exclude analyzing extreme Islamism of non-Egyptian origins. This
case study relies on the moral disengagement theory to shed light on
the ideological evolution of extremism in Egypt. The goal of this case
study is to help in understanding extreme-Islamism adverse to the
mainstream Islam; therefore, understanding the concept here should
help in preventing similar groups from threatening the international
community.
Abstract: This paper presents a comparative study of statistical methods for the multi-response surface optimization of a cryogenic freezing process. Taguchi design and analysis and steepest ascent methods based on the desirability function were conducted to ascertain the influential factors of a cryogenic freezing process and their optimal levels. The more preferable levels of the set point, exhaust fan speed, retention time and flow direction are set at -90oC, 20 Hz, 18 minutes and Counter Current, respectively. The overall desirability level is 0.7044.
Abstract: In order to investigate a PROX microreactor
performance, two-dimensional modeling of the reacting flow
between two parallel plates is performed through a finite volume
method using an improved SIMPLE algorithm. A three-step surface
kinetics including hydrogen oxidation, carbon monoxide oxidation
and water-gas shift reaction is applied for a Pt-Fe/γ-Al2O3 catalyst
and operating temperatures of about 100ºC. Flow pattern, pressure
field, temperature distribution, and mole fractions of species are
found in the whole domain for all cases. Also, the required reactive
length for removing carbon monoxide from about 2% to less than 10
ppm is found. Furthermore, effects of hydraulic diameter, wall
temperature, and inlet mole fraction of air and water are investigated
by considering carbon monoxide selectivity and conversion. It is
found that air and water addition may improve the performance of
the microreactor in carbon monoxide removal in such operating
conditions; this is in agreement with the pervious published results.
Abstract: This paper has as its main aim to analyse how
corporate web pages can become an essential tool in order to detect
strategic trends by firms or sectors, and even a primary source for
benchmarking. This technique has made it possible to identify the key
issues in the strategic management of the most excellent large Spanish
firms and also to describe trends in their long-range planning, a way of
working that can be generalised to any country or firm group. More
precisely, two objectives were sought. The first one consisted in showing
the way in which corporate websites make it possible to obtain direct
information about the strategic variables which can define firms. This
tool is dynamic (since web pages are constantly updated) as well as
direct and reliable, since the information comes from the firm itself, not
from comments of third parties (such as journalists, academicians,
consultants...). When this information is analysed for a group of firms,
one can observe their characteristics in terms of both managerial tasks
and business management. As for the second objective, the methodology
proposed served to describe the corporate profile of the large Spanish
enterprises included in the Ibex35 (the Ibex35 or Iberia Index is the
reference index in the Spanish Stock Exchange and gathers periodically
the 35 most outstanding Spanish firms). An attempt is therefore made to
define the long-range planning that would be characteristic of the largest
Spanish firms.
Abstract: This paper presents a systematic approach for
designing Static Synchronous Series Compensator (SSSC) based
supplementary damping controllers for damping low frequency
oscillations in a single-machine infinite-bus power system. The
design problem of the proposed controller is formulated as an
optimization problem and RCGA is employed to search for optimal
controller parameters. By minimizing the time-domain based
objective function, in which the deviation in the oscillatory rotor
speed of the generator is involved; stability performance of the
system is improved. Simulation results are presented and compared
with a conventional method of tuning the damping controller
parameters to show the effectiveness and robustness of the proposed
design approach.
Abstract: In this paper, we present a method for edge
segmentation of satellite images based on 2-D Phase Congruency
(PC) model. The proposed approach is composed by two steps: The
contextual non linear smoothing algorithm (CNLS) is used to smooth
the input images. Then, the 2D stretched Gabor filter (S-G filter)
based on proposed angular variation is developed in order to avoid
the multiple responses in the previous work. An assessment of our
proposed method performance is provided in terms of accuracy of
satellite image edge segmentation. The proposed method is compared
with others known approaches.
Abstract: This paper proposes a method to improve the shortest
path problem on a NURBS (Non-uniform rational basis spline) surfaces.
It comes from an application of the theory in classic differential
geometry on surfaces and can improve the distance problem not only
on surfaces but in the Euclidean 3-space R3 .
Abstract: In this paper, a new alignment method based on the particle swarm optimization (PSO) technique is presented. The PSO algorithm is used for locating the optimal coupling position with the highest optical power with three-degrees of freedom alignment. This algorithm gives an interesting results without a need to go thru the complex mathematical modeling of the alignment system. The proposed algorithm is validated considering practical tests considering the alignment of two Single Mode Fibers (SMF) and the alignment of SMF and PCF fibers.
Abstract: This paper considers a robust recovery of sparse frequencies
from partial phase-only measurements. With the proposed
method, sparse frequencies can be reconstructed, which makes full
use of the sparse distribution in the Fourier representation of the
complex-valued time signal. Simulation experiments illustrate the
proposed method-s advantages over conventional methods in both
noiseless and additive white Gaussian noise cases.
Abstract: The aim of the article is extending and developing
econometrics and network structure based methods which are able to
distinguish price manipulation in Tehran stock exchange. The
principal goal of the present study is to offer model for
approximating price manipulation in Tehran stock exchange. In order
to do so by applying separation method a sample consisting of 397
companies accepted at Tehran stock exchange were selected and
information related to their price and volume of trades during years
2001 until 2009 were collected and then through performing runs
test, skewness test and duration correlative test the selected
companies were divided into 2 sets of manipulated and non
manipulated companies. In the next stage by investigating
cumulative return process and volume of trades in manipulated
companies, the date of starting price manipulation was specified and
in this way the logit model, artificial neural network, multiple
discriminant analysis and by using information related to size of
company, clarity of information, ratio of P/E and liquidity of stock
one year prior price manipulation; a model for forecasting price
manipulation of stocks of companies present in Tehran stock
exchange were designed. At the end the power of forecasting models
were studied by using data of test set. Whereas the power of
forecasting logit model for test set was 92.1%, for artificial neural
network was 94.1% and multi audit analysis model was 90.2%;
therefore all of the 3 aforesaid models has high power to forecast
price manipulation and there is no considerable difference among
forecasting power of these 3 models.
Abstract: Clustering is one of an interesting data mining topics
that can be applied in many fields. Recently, the problem of cluster
analysis is formulated as a problem of nonsmooth, nonconvex optimization,
and an algorithm for solving the cluster analysis problem
based on nonsmooth optimization techniques is developed. This
optimization problem has a number of characteristics that make it
challenging: it has many local minimum, the optimization variables
can be either continuous or categorical, and there are no exact
analytical derivatives. In this study we show how to apply a particular
class of optimization methods known as pattern search methods
to address these challenges. These methods do not explicitly use
derivatives, an important feature that has not been addressed in
previous studies. Results of numerical experiments are presented
which demonstrate the effectiveness of the proposed method.
Abstract: In this paper, we focus on the use of knowledge bases
in two different application areas – control of systems with unknown
or strongly nonlinear models (i.e. hardly controllable by the classical
methods), and robot motion planning in eight directions. The first
one deals with fuzzy logic and the paper presents approaches for
setting and aggregating the rules of a knowledge base. Te second one
is concentrated on a case-based reasoning strategy for finding the
path in a planar scene with obstacles.