Abstract: The equations governing the flow of an electrically conducting, incompressible viscous fluid over an infinite flat plate in the presence of a magnetic field are investigated using the homotopy perturbation method (HPM) with Padé approximants (PA) and 4th order Runge–Kutta method (4RKM). Approximate analytical and numerical solutions for the velocity field and heat transfer are obtained and compared with each other, showing excellent agreement. The effects of the magnetic parameter and Prandtl number on velocity field, shear stress, temperature and heat transfer are discussed as well.
Abstract: Honeycomb sandwich panels are increasingly used in the construction of space vehicles because of their outstanding strength, stiffness and light weight properties. However, the use of honeycomb sandwich plates comes with difficulties in the design process as a result of the large number of design variables involved, including composite material design, shape and geometry. Hence, this work deals with the presentation of an optimal design of hexagonal honeycomb sandwich structures subjected to space environment. The optimization process is performed using a set of algorithms including the gravitational search algorithm (GSA). Numerical results are obtained and presented for a set of algorithms. The results obtained by the GSA algorithm are much better compared to other algorithms used in this study.
Abstract: This paper addresses the design of predictive
networked controller with adaptation of a communication delay. The
networked control system contains random delays from sensor to
controller and from controller to actuator. The proposed predictive
controller includes an adaptation loop which decreases the influence
of communication delay on the control performance. Also, the
predictive controller contains a filter which improves the robustness
of the control system. The performance of the proposed adaptive
predictive controller is demonstrated by simulation results in
comparison with PI controller and predictive controller with constant
delay.
Abstract: Diabetes Mellitus is a chronic metabolic disorder, where the improper management of the blood glucose level in the diabetic patients will lead to the risk of heart attack, kidney disease and renal failure. This paper attempts to enhance the diagnostic accuracy of the advancing blood glucose levels of the diabetic patients, by combining principal component analysis and wavelet neural network. The proposed system makes separate blood glucose prediction in the morning, afternoon, evening and night intervals, using dataset from one patient covering a period of 77 days. Comparisons of the diagnostic accuracy with other neural network models, which use the same dataset are made. The comparison results showed overall improved accuracy, which indicates the effectiveness of this proposed system.
Abstract: The automatic classification of non stationary signals is an important practical goal in several domains. An essential classification task is to allocate the incoming signal to a group associated with the kind of physical phenomena producing it. In this paper, we present a modular system composed by three blocs: 1) Representation, 2) Dimensionality reduction and 3) Classification. The originality of our work consists in the use of a new wavelet called "Ben wavelet" in the representation stage. For the dimensionality reduction, we propose a new algorithm based on the random projection and the principal component analysis.
Abstract: With the hardware technology advancing, the cost of
storing is decreasing. Thus there is an urgent need for new techniques
and tools that can intelligently and automatically assist us in
transferring this data into useful knowledge. Different techniques of
data mining are developed which are helpful for handling these large
size databases [7]. Data mining is also finding its role in the field of
biotechnology. Pedigree means the associated ancestry of a crop
variety. Genetic diversity is the variation in the genetic composition
of individuals within or among species. Genetic diversity depends
upon the pedigree information of the varieties. Parents at lower
hierarchic levels have more weightage for predicting genetic
diversity as compared to the upper hierarchic levels. The weightage
decreases as the level increases. For crossbreeding, the two varieties
should be more and more genetically diverse so as to incorporate the
useful characters of the two varieties in the newly developed variety.
This paper discusses the searching and analyzing of different possible
pairs of varieties selected on the basis of morphological characters,
Climatic conditions and Nutrients so as to obtain the most optimal
pair that can produce the required crossbreed variety. An algorithm
was developed to determine the genetic diversity between the
selected wheat varieties. Cluster analysis technique is used for
retrieving the results.
Abstract: This study fabricates p-type Ni1−xO:Li/n-Si heterojunction solar cells (P+/n HJSCs) by using radio frequency (RF) magnetron sputtering and investigates the effect of substrate temperature on photovoltaic cell properties. Grazing incidence x-ray diffraction, four point probe, and ultraviolet-visible-near infrared discover the optoelectrical properties of p-Ni1-xO thin films. The results show that p-Ni1-xO thin films deposited at 300 oC has the highest grain size (22.4 nm), average visible transmittance (~42%), and electrical resistivity (2.7 Ωcm). However, the conversion efficiency of cell is shown only 2.33% which is lower than the cell (3.39%) fabricated at room temperature. This result can be mainly attributed to interfacial layer thickness (SiOx) reduces from 2.35 nm to 1.70 nm, as verified by high-resolution transmission electron microscopy.
Abstract: The previous researches focused on the influence of
anthropogenic greenhouse gases exerting global warming, but not
consider whether desert sand may warm the planet, this could be
improved by accounting for sand's physical and geometric properties.
Here we show, sand particles (because of their geometry) at the desert
surface form an extended surface of up to 1 + π/4 times the planar area
of the desert that can contact sunlight, and at shallow depths of the
desert form another extended surface of at least 1 + π times the planar
area that can contact air. Based on this feature, an enhanced heat
exchange system between sunlight, desert sand, and air in the spaces
between sand particles could be built up automatically, which can
increase capture of solar energy, leading to rapid heating of the sand
particles, and then the heating of sand particles will dramatically heat
the air between sand particles. The thermodynamics of deserts may
thus have contributed to global warming, especially significant to
future global warming if the current desertification continues to
expand.
Abstract: Intelligent schools are those which use IT devices and
technologies as media software, hardware and networks to improve
learning process. On the other hand Strategic management is a field
that deals with the major intended and emergent initiatives taken by
general managers on behalf of owners, involving utilization of resources, to enhance the performance of firms in their external environments. Here, we present a model Strategic Management System that has been applied on some schools and have made strict
improvement.
Abstract: Optical network uses a tool for routing called Latin
router. These routers use particular algorithms for routing. For
example, we can refer to LDF algorithm that uses backtracking (one
of CSP methods) for problem solving. In this paper, we proposed
new approached for completion routing table (DRA&CRA
algorithm) and compare with pervious proposed ways and showed
numbers of backtracking, blocking and run time for DRA algorithm
less than LDF and CRA algorithm.
Abstract: This paper proposes a neural network weights and
topology optimization using genetic evolution and the
backpropagation training algorithm. The proposed crossover and
mutation operators aims to adapt the networks architectures and
weights during the evolution process. Through a specific inheritance
procedure, the weights are transmitted from the parents to their
offsprings, which allows re-exploitation of the already trained
networks and hence the acceleration of the global convergence of the
algorithm. In the preprocessing phase, a new feature extraction
method is proposed based on Legendre moments with the Maximum
entropy principle MEP as a selection criterion. This allows a global
search space reduction in the design of the networks. The proposed
method has been applied and tested on the well known MNIST
database of handwritten digits.
Abstract: This work provides a practical method for the
development of rural road networks in rural areas of developing
countries. The proposed methodology enables to determine
obligatory points in the rural road network maximizing the number of
settlements that have access to basic services within a given
maximum distance. The proposed methodology is simple and
practical, hence, highly applicable to real-world scenarios, as
demonstrated in the definition of the road network for the rural areas
of Nepal.
Abstract: Mobile ad hoc network is a collection of mobile
nodes communicating through wireless channels without any
existing network infrastructure or centralized administration.
Because of the limited transmission range of wireless network
interfaces, multiple "hops" may be needed to exchange data
across the network. Consequently, many routing algorithms
have come into existence to satisfy the needs of
communications in such networks. Researchers have
conducted many simulations comparing the performance of
these routing protocols under various conditions and
constraints. One question that arises is whether speed of nodes
affects the relative performance of routing protocols being
studied. This paper addresses the question by simulating two
routing protocols AODV and DSDV. Protocols were
simulated using the ns-2 and were compared in terms of
packet delivery fraction, normalized routing load and average
delay, while varying number of nodes, and speed.
Abstract: One of the efficient factors in comprehensive
development of an area is to provide water sources and on the other
hand the appropriate management of them. Population growth and
nourishment security for such a population necessitate the
achievement of constant development besides the reforming of
traditional management in order to increase the profit of sources; In
this case, the constant exploitation of sources for the next generations
will be considered in this program. The achievement of this
development without the consideration and possibility of water
development will be too difficult. Zayanderood basin with 41500
areas in square kilometers contains 7 sub-basins and 20 units of
hydrologic. In this basin area, from the entire environment
descending, just a small part will enter into the river currents and the
rest will be out of efficient usage by various ways. The most
important surface current of this basin is Zayanderood River with
403 kilometers length which is originated from east slopes of Zagros
mount and after draining of this basin area it will enter into
Gaavkhooni pond. The existence of various sources and
consumptions of water in Zayanderood basin, water transfer of the
other basin areas into this basin, of course the contradiction between
the upper and lower beneficiaries, the existence of worthwhile
natural ecosystems such as Gaavkhooni swamp in this basin area and
finally, the drought condition and lack of water in this area all
necessitate the existence of comprehensive management of water
sources in this central basin area of Iran as this method is a kind of
management which considers the development and the management
of water sources as an equilibrant way to increase the economical
and social benefits. In this study, it is tried to survey the network of
surface water sources of basin in upper and lower sections; at the
most, according to the difficulties and deficiencies of an efficient
management of water sources in this basin area, besides the
difficulties of water draining and the destructive phenomenon of
flood-water, the appropriate guidelines according to the region
conditions are presented in order to prevent the deviation of water in
upper sections and development of regions in lower sections of
Zayanderood dam.
Abstract: In this paper, we investigate multihop polling and data gathering schemes in layered sensor networks in order to extend the life time of the networks. A network consists of three layers. The lowest layer contains sensors. The middle layer contains so called super nodes with higher computational power, energy supply and longer transmission range than sensor nodes. The top layer contains a sink node. A node in each layer controls a number of nodes in lower layer by polling mechanism to gather data. We will present four types of data gathering schemes: intermediate nodes do not queue data packet, queue single packet, queue multiple packets and aggregate data, to see which data gathering scheme is more energy efficient for multihop polling in layered sensor networks.
Abstract: Classification of Persian printed numeral characters
has been considered and a proposed system has been introduced. In
representation stage, for the first time in Persian optical character
recognition, extended moment invariants has been utilized as
characters image descriptor. In classification stage, four different
classifiers namely minimum mean distance, nearest neighbor rule,
multi layer perceptron, and fuzzy min-max neural network has been
used, which first and second are traditional nonparametric statistical
classifier. Third is a well-known neural network and forth is a kind of
fuzzy neural network that is based on utilizing hyperbox fuzzy sets.
Set of different experiments has been done and variety of results has
been presented. The results showed that extended moment invariants
are qualified as features to classify Persian printed numeral
characters.
Abstract: The aim of this study is to determine the basic information and communication technology (ICT) skills that may be needed by students studying in the 8th grade of the primary education in their cooperative project works implemented via the Internet. Within the scope of the study, the curriculum used for European Computer Driving License (ECDL) and the curriculum used in Turkey are also compared in terms of the ability to use ICT, which is aimed to be provided to the students. The research population of the study, during which the pre test – post test control group experimental model was used, consisted of 40 students from three different schools. In the first stage of the study, the skills that might be needed by students for their cooperative project works implemented via the Internet were determined through examination of the completed Comenious, e – twinning and WorldLinks projects. In the second stage of the study, the curriculums of the Turkish Ministry of National Education (MEB) and ECDL were evaluated by seven different teachers in line with these skills. Also in this study the ECDL and MEB curriculums were compared in terms of capability to provide the skills to implement cooperative projects via the Internet. In line with the findings of the study, the skills that might be needed by students to implement cooperative projects via the Internet were outlined, and existence of a significant difference was established in favor of the ECDL curriculum upon comparison of both curriculums in accordance with this outline (U = 50,500; p
Abstract: Recently, genetic algorithms (GA) and particle swarm optimization (PSO) technique have attracted considerable attention among various modern heuristic optimization techniques. Since the two approaches are supposed to find a solution to a given objective function but employ different strategies and computational effort, it is appropriate to compare their performance. This paper presents the application and performance comparison of PSO and GA optimization techniques, for Thyristor Controlled Series Compensator (TCSC)-based controller design. The design objective is to enhance the power system stability. The design problem of the FACTS-based controller is formulated as an optimization problem and both the PSO and GA optimization techniques are employed to search for optimal controller parameters. The performance of both optimization techniques in terms of computational time and convergence rate is compared. Further, the optimized controllers are tested on a weakly connected power system subjected to different disturbances, and their performance is compared with the conventional power system stabilizer (CPSS). The eigenvalue analysis and non-linear simulation results are presented and compared to show the effectiveness of both the techniques in designing a TCSC-based controller, to enhance power system stability.
Abstract: In this paper, a new face recognition method based on
PCA (principal Component Analysis), LDA (Linear Discriminant
Analysis) and neural networks is proposed. This method consists of
four steps: i) Preprocessing, ii) Dimension reduction using PCA, iii)
feature extraction using LDA and iv) classification using neural
network. Combination of PCA and LDA is used for improving the
capability of LDA when a few samples of images are available and
neural classifier is used to reduce number misclassification caused by
not-linearly separable classes. The proposed method was tested on
Yale face database. Experimental results on this database
demonstrated the effectiveness of the proposed method for face
recognition with less misclassification in comparison with previous
methods.
Abstract: The absolute Cu atoms density in Cu(2S1/22P1/2)
ground state has been measured by Resonance Optical Absorption
(ROA) technique in a DC magnetron sputtering deposition with
argon. We measured these densities under variety of operation
conditions: pressure from 0.6 μbar to 14 μbar, input power from
10W to 200W and N2 mixture from 0% to 100%. For measuring the
gas temperature, we used the simulation of N2 rotational spectra
with a special computer code. The absolute number density of Cu
atoms decreases with increasing the N2 percentage of buffer gas at
any conditions of this work. But the deposition rate, is not decreased
with the same manner. The deposition rate variation is very small
and in the limit of quartz balance measuring equipment accuracy. So
we conclude that decrease in the absolute number density of Cu
atoms in magnetron plasma has not a big effect on deposition rate,
because the diffusion of Cu atoms to the chamber volume and
deviation of Cu atoms from direct path (towards the substrate)
decreases with increasing of N2 percentage of buffer gas. This is
because of the lower mass of N2 atoms compared to the argon ones.