Abstract: We report here, the results of molecular dynamics
simulation of p-doped (Ga-face)GaN over n-doped (Siface)(
0001)4H-SiC hetero-epitaxial material system with one-layer
each of Ga-flux and (Al-face)AlN, as the interface materials, in the
form of, the total Density of States (DOS). It is found that the total
DOS at the Fermi-level for the heavily p-doped (Ga-face)GaN and ndoped
(Si-face)4H-SiC hetero-epitaxial system, with one layer of
(Al-face)AlN as the interface material, is comparatively higher than
that of the various cases studied, indicating that there could be good
vertical conduction across the (Ga-face)GaN over (Si-face)(0001)4HSiC
hetero-epitaxial material system.
Abstract: In present paper we proposed a simple and effective method to compress an image. Here we found success in size reduction of an image without much compromising with it-s quality. Here we used Haar Wavelet Transform to transform our original image and after quantization and thresholding of DWT coefficients Run length coding and Huffman coding schemes have been used to encode the image. DWT is base for quite populate JPEG 2000 technique.
Abstract: Elastic and inelastic scattering of α-particles by 9Be nuclei at different incident energies have been analyzed. Optical model parameters (OMPs) of α-particles elastic scattering by 9Be at different energies have been obtained. Coupled Reaction Channel (CRC) of elastic scattering, inelastic scattering and transfer reaction has been calculated using Fresco Code. The effect of involving CRC calculations on the analysis of differential cross section has been studied. The transfer reaction of (5He) in the reaction 9Be(α,9Be)α has been studied. The spectroscopic factor of 9Be≡α+5He has been extracted.
Abstract: In this paper, we consider the problem of Popular Matching of strictly ordered preference lists. A Popular Matching is not guaranteed to exist in any network. We propose an IDbased, constant space, self-stabilizing algorithm that converges to a Maximum Popular Matching an optimum solution, if one exist. We show that the algorithm stabilizes in O(n5) moves under any scheduler (daemon).
Abstract: The particular interests of this paper is to explore if the simple Genetic Algorithms (GA) starts with population of only two individuals and applying different crossover technique over these parents to produced 104 children, each one has different attributes inherited from their parents; is better than starting with population of 100 individuals; and using only one type crossover (order crossover OX). For this reason we implement GA with 52 different crossover techniques; each one produce two children; which means 104 different children will be produced and this may discover more search space, also we implement classic GA with order crossover and many experiments were done over 3 Travel Salesman Problem (TSP) to find out which method is better, and according to the results we can say that GA with Multi-crossovers is much better.
Abstract: In this article, we propose a methodology for the
characterization of the suspended matter along Algiers-s bay. An
approach by multi layers perceptron (MLP) with training by back
propagation of the gradient optimized by the algorithm of Levenberg
Marquardt (LM) is used. The accent was put on the choice of the
components of the base of training where a comparative study made
for four methods: Random and three alternatives of classification by
K-Means. The samples are taken from suspended matter image,
obtained by analytical model based on polynomial regression by
taking account of in situ measurements. The mask which selects the
zone of interest (water in our case) was carried out by using a multi
spectral classification by ISODATA algorithm. To improve the
result of classification, a cleaning of this mask was carried out using
the tools of mathematical morphology. The results of this study
presented in the forms of curves, tables and of images show the
founded good of our methodology.
Abstract: Based on the thermodynamic theory, the dependence of
sublimation energy of metal on temperature and pressure is discussed,
and the results indicate that the sublimation energy decreases linearly
with the increase of temperature and pressure. Combined with this
result, the blow-off impulse of aluminum induced by pulsed X-ray is
simulated by smoothed particle hydrodynamics (SPH) method. The
numerical results show that, while the change of sublimation energy
with temperature and pressure is considered, the blow-off impulse of
aluminum is larger than the case that the sublimation energy is
assumed to be a constant.
Abstract: The electrical potentials generated during eye movements and blinks are one of the main sources of artifacts in Electroencephalogram (EEG) recording and can propagate much across the scalp, masking and distorting brain signals. In recent times, signal separation algorithms are used widely for removing artifacts from the observed EEG data. In this paper, a recently introduced signal separation algorithm Mutual Information based Least dependent Component Analysis (MILCA) is employed to separate ocular artifacts from EEG. The aim of MILCA is to minimize the Mutual Information (MI) between the independent components (estimated sources) under a pure rotation. Performance of this algorithm is compared with eleven popular algorithms (Infomax, Extended Infomax, Fast ICA, SOBI, TDSEP, JADE, OGWE, MS-ICA, SHIBBS, Kernel-ICA, and RADICAL) for the actual independence and uniqueness of the estimated source components obtained for different sets of EEG data with ocular artifacts by using a reliable MI Estimator. Results show that MILCA is best in separating the ocular artifacts and EEG and is recommended for further analysis.
Abstract: We present a hybrid architecture of recurrent neural
networks (RNNs) inspired by hidden Markov models (HMMs). We
train the hybrid architecture using genetic algorithms to learn and
represent dynamical systems. We train the hybrid architecture on a
set of deterministic finite-state automata strings and observe the
generalization performance of the hybrid architecture when presented
with a new set of strings which were not present in the training data
set. In this way, we show that the hybrid system of HMM and RNN
can learn and represent deterministic finite-state automata. We ran
experiments with different sets of population sizes in the genetic
algorithm; we also ran experiments to find out which weight
initializations were best for training the hybrid architecture. The
results show that the hybrid architecture of recurrent neural networks
inspired by hidden Markov models can train and represent dynamical
systems. The best training and generalization performance is
achieved when the hybrid architecture is initialized with random real
weight values of range -15 to 15.
Abstract: Unlike the best effort service provided by the internet
today, next-generation wireless networks will support real-time
applications. This paper proposes an adaptive early packet discard
(AEPD) policy to improve the performance of the real time TCP
traffic over ATM networks and avoid the fragmentation problem.
Three main aspects are incorporated in the proposed policy. First,
providing quality-of-service (QoS) guaranteed for real-time
applications by implementing a priority scheduling. Second,
resolving the partially corrupted packets problem by differentiating
the buffered cells of one packet from another. Third, adapting a
threshold dynamically using Fuzzy logic based on the traffic
behavior to maintain a high throughput under a variety of load
conditions. The simulation is run for two priority classes of the input
traffic: real time and non-real time classes. Simulation results show
that the proposed AEPD policy improves throughput and fairness
over that using static threshold under the same traffic conditions.
Abstract: Cogeneration may be defined as a system which
contains electricity production and regain of the thermo value of
exhaust gases simultaneously. The examination is based on the data-s
of an active cogeneration plant. This study, it is aimed to determine
which component of the system should be revised first to raise the
efficiency and decrease the loss of exergy. For this purpose, second
law analysis of thermodynamics is applied to each component due to
consider the effects of environmental conditions and take the quality
of energy into consideration as well as the quantity of it. The exergy
balance equations are produced and exergy loss is calculated for each
component. 44,44 % loss of exergy in heat exchanger, 29,59 % in
combustion chamber, 18,68 % in steam boiler, 5,25 % in gas turbine
and 2,03 % in compressor is calculated.
Abstract: In this article, an adaptive least-squares mixed finite element method is studied for pseudo-parabolic integro-differential equations. The solutions of least-squares mixed weak formulation and mixed finite element are proved. A posteriori error estimator is constructed based on the least-squares functional and the posteriori errors are obtained.
Abstract: The ability to detect and classify the type of fault
plays a great role in the protection of power system. This procedure
is required to be precise with no time consumption. In this paper
detection of fault type has been implemented using wavelet analysis
together with wavelet entropy principle. The simulation of power
system is carried out using PSCAD/EMTDC. Different types of
faults were studied obtaining various current waveforms. These
current waveforms were decomposed using wavelet analysis into
different approximation and details. The wavelet entropy of such
decompositions is analyzed reaching a successful methodology for
fault classification. The suggested approach is tested using different
fault types and proven successful identification for the type of fault.
Abstract: Neem is a highly heterozygous and commercially
important perennial plant. Conventionally, it is propagated by seeds
which loose viability within two weeks. Strictly cross pollinating
nature of the plant causes serious barrier to the genetic improvement
by conventional methods. Alternative methods of tree improvement
such as somatic hybridization, mutagenesis and genetic
transformation require an efficient in vitro plant regeneration system.
In this regard, somatic embryogenesis particularly secondary somatic
embryogenesis may offer an effective system for large scale plant
propagation without affecting the clonal fidelity of the regenerants. It
can be used for synthetic seed production, which further bolsters
conservation of this tree species which is otherwise very difficult
The present report describes the culture conditions necessary to
induce and maintain repetitive somatic embryogenesis, for the first
time, in neem. Out of various treatments tested, the somatic embryos
were induced directly from immature zygotic embryos of neem on
MS + TDZ (0.1 μM) + ABA (4 μM), in more than 76 % cultures.
Direct secondary somatic embryogenesis occurred from primary
somatic embryos on MS + IAA (5 μM) + GA3 (5 μM) in 12.5 %
cultures. Embryogenic competence of the explant as well as of the
primary embryos was maintained for a long period by repeated
subcultures at frequent intervals. A maximum of 10 % of these
somatic embryos were converted into plantlets.
Abstract: A Cable-Driven Locomotion Interface provides a low
inertia haptic interface and is used as a way of enabling the user
to walk and interact with virtual surfaces. These surfaces generate
Cartesian wrenches which must be optimized for each motorized
reel in order to reproduce a haptic sensation in both feet. However,
the use of wrench control requires a measure of the cable tensions
applied to the moving platform. The latter measure may be inaccurate
if it is based on sensors located near the reel. Moreover, friction
hysteresis from the reel moving parts needs to be compensated
for with an evaluation of low angular velocity of the motor shaft.
Also, the pose of the platform is not known precisely due to cable
sagging and mechanical deformation. This paper presents a non-ideal
motorized reel design with its corresponding control strategy that
aims at overcoming the aforementioned issues. A transfert function
of the reel based on frequency responses in function of cable tension
and cable length is presented with an optimal adaptative PIDF
controller. Finally, an hybrid position/tension control is discussed with
an analysis of the stability for achieving a complete functionnality of
the haptic platform.
Abstract: The paper investigates parallel channel instabilities of
natural circulation boiling water reactor. A thermal-hydraulic model
is developed to simulate two-phase flow behavior in the natural circulation boiling water reactor (NCBWR) with the incorporation of
ex-core components and recirculation loop such as steam separator, down-comer, lower-horizontal section and upper-horizontal section
and then, numerical analysis is carried out for parallel channel
instabilities of the reactor undergoing both in-phase and out-of-phase
modes of oscillations. To analyze the relative effect on stability of the reactor due to inclusion of various ex-core components and
recirculation loop, marginal stable point is obtained at a particular inlet enthalpy of the reactor core without the inclusion of ex-core
components and recirculation loop and then with the inclusion of the
same. Numerical simulations are also conducted to determine the
relative dominance between two modes of oscillations i.e. in-phase and out-of-phase. Simulations are also carried out when the channels
are subjected to asymmetric power distribution keeping the inlet enthalpy same.
Abstract: Hydrogen sulfide (H2S) is a very toxic gas that is produced in very large quantities in the oil and gas industry. It cannot be flared to the atmosphere and Claus process based gas plants are used to recover the sulfur and convert the hydrogen to water. In this paper, we present optical characterization of an atmospheric pressure microwave plasma torch for H2S dissociation into hydrogen and sulfur. The torch is operated at 2.45 GHz with power up to 2 kW. Three different gases can simultaneously be injected in the plasma torch. Visual imaging and optical emission spectroscopy are used to characterize the plasma for varying gas flow rates and microwave power. The plasma length, emission spectra and temperature are presented. The obtained experimental results validate our earlier published simulation results of plasma torch.
Abstract: This paper proposes different methods for estimation
of the harmonic currents of the single-phase diode bridge rectifier. Both simple and advanced methods are compared and the models are
put into a context of practical use for calculating the harmonic distortion in a typical application. Finally, the different models are
compared to measurements of a real application and convincing results are achieved.
Abstract: In this paper we propose a robust adaptive fuzzy
controller for a class of nonlinear system with unknown dynamic.
The method is based on type-2 fuzzy logic system to approximate
unknown non-linear function. The design of the on-line adaptive
scheme of the proposed controller is based on Lyapunov technique.
Simulation results are given to illustrate the effectiveness of the
proposed approach.
Abstract: Horizontal wells are proven to be better producers
because they can be extended for a long distance in the pay zone.
Engineers have the technical means to forecast the well productivity
for a given horizontal length. However, experiences have shown that
the actual production rate is often significantly less than that of
forecasted. It is a difficult task, if not impossible to identify the real
reason why a horizontal well is not producing what was forecasted.
Often the source of problem lies in the drilling of horizontal section
such as permeability reduction in the pay zone due to mud invasion
or snaky well patterns created during drilling. Although drillers aim
to drill a constant inclination hole in the pay zone, the more frequent
outcome is a sinusoidal wellbore trajectory. The two factors, which
play an important role in wellbore tortuosity, are the inclination and
side force at bit. A constant inclination horizontal well can only be
drilled if the bit face is maintained perpendicular to longitudinal axis
of bottom hole assembly (BHA) while keeping the side force nil at
the bit. This approach assumes that there exists no formation force at
bit. Hence, an appropriate BHA can be designed if bit side force and
bit tilt are determined accurately. The Artificial Neural Network
(ANN) is superior to existing analytical techniques. In this study, the
neural networks have been employed as a general approximation tool
for estimation of the bit side forces. A number of samples are
analyzed with ANN for parameters of bit side force and the results
are compared with exact analysis. Back Propagation Neural network
(BPN) is used to approximation of bit side forces. Resultant low
relative error value of the test indicates the usability of the BPN in
this area.