Abstract: Avoiding learning failures in mathematics e-learning environments caused by emotional problems in students with autism has become an important topic for combining of special education with information and communications technology. This study presents an adaptive emotional adjustment model in mathematics e-learning for students with autism, emphasizing the lack of emotional perception in mathematics e-learning systems. In addition, an emotion classification for students with autism was developed by inducing emotions in mathematical learning environments to record changes in the physiological signals and facial expressions of students. Using these methods, 58 emotional features were obtained. These features were then processed using one-way ANOVA and information gain (IG). After reducing the feature dimension, methods of support vector machines (SVM), k-nearest neighbors (KNN), and classification and regression trees (CART) were used to classify four emotional categories: baseline, happy, angry, and anxious. After testing and comparisons, in a situation without feature selection, the accuracy rate of the SVM classification can reach as high as 79.3-%. After using IG to reduce the feature dimension, with only 28 features remaining, SVM still has a classification accuracy of 78.2-%. The results of this research could enhance the effectiveness of eLearning in special education.
Abstract: Inconel 718, a nickel based super-alloy is an
extensively used alloy, accounting for about 50% by weight of
materials used in an aerospace engine, mainly in the gas turbine
compartment. This is owing to their outstanding strength and
oxidation resistance at elevated temperatures in excess of 5500 C.
Machining is a requisite operation in the aircraft industries for the
manufacture of the components especially for gas turbines. This
paper is concerned with optimization of the surface roughness when
turning Inconel 718 with cermet inserts. Optimization of turning
operation is very useful to reduce cost and time for machining. The
approach is based on Response Surface Method (RSM). In this work,
second-order quadratic models are developed for surface roughness,
considering the cutting speed, feed rate and depth of cut as the cutting
parameters, using central composite design. The developed models
are used to determine the optimum machining parameters. These
optimized machining parameters are validated experimentally, and it
is observed that the response values are in reasonable agreement with
the predicted values.
Abstract: The modern queueing theory is one of the powerful
tools for a quantitative and qualitative analysis of communication systems, computer networks, transportation systems, and many other technical systems. The paper is designated to the analysis of queueing
systems, arising in the networks theory and communications theory
(called open queueing network). The authors of this research in the
sphere of queueing theory present the theorem about the law of the iterated logarithm (LIL) for the queue length of a customers in open
queueing network and its application to the mathematical model of
the open message switching system.
Abstract: The main objective developed in this paper is to find a
graphic technique for modeling, simulation and diagnosis of the
industrial systems. This importance is much apparent when it is about
a complex system such as the nuclear reactor with pressurized water
of several form with various several non-linearity and time scales. In
this case the analytical approach is heavy and does not give a fast
idea on the evolution of the system. The tool Bond Graph enabled us
to transform the analytical model into graphic model and the
software of simulation SYMBOLS 2000 specific to the Bond Graphs
made it possible to validate and have the results given by the
technical specifications. We introduce the analysis of the problem
involved in the faults localization and identification in the complex
industrial processes. We propose a method of fault detection applied
to the diagnosis and to determine the gravity of a detected fault. We
show the possibilities of application of the new diagnosis approaches
to the complex system control. The industrial systems became
increasingly complex with the faults diagnosis procedures in the
physical systems prove to become very complex as soon as the
systems considered are not elementary any more. Indeed, in front of
this complexity, we chose to make recourse to Fault Detection and
Isolation method (FDI) by the analysis of the problem of its control
and to conceive a reliable system of diagnosis making it possible to
apprehend the complex dynamic systems spatially distributed applied
to the standard pressurized water nuclear reactor.
Abstract: The objective of the present work is to conduct
investigations leading to a more complete explanation of single phase
natural convective heat transfer in an enclosure with fin utilizing
nano fluids. The nano fluid used, which is composed of Aluminum
oxide nano particles in suspension of Ethylene glycol, is provided at
various volume fractions. The study is carried out numerically for a
range of Rayleigh numbers, fin heights and aspect ratio. The flow and
temperature distributions are taken to be two-dimensional. Regions
with the same velocity and temperature distributions are identified as
symmetry of sections. One half of such a rectangular region is chosen
as the computational domain taking into account the symmetry about
the fin. Transport equations are modeled by a stream functionvorticity
formulation and are solved numerically by finite-difference
schemes. Comparisons with previously published works on the basis
of special cases are done. Results are presented in the form of
streamline, vector and isotherm plots as well as the variation of local
Nusselt number along the fin under different conditions.
Abstract: An active suspension system has been proposed to
improve the ride comfort. A quarter-car 2 degree-of-freedom (DOF)
system is designed and constructed on the basis of the concept of a
four-wheel independent suspension to simulate the actions of an
active vehicle suspension system. The purpose of a suspension
system is to support the vehicle body and increase ride comfort. The
aim of the work described in the paper was to illustrate the
application of fuzzy logic technique to the control of a continuously
damping automotive suspension system. The ride comfort is
improved by means of the reduction of the body acceleration caused
by the car body when road disturbances from smooth road and real
road roughness.
The paper describes also the model and controller used in the
study and discusses the vehicle response results obtained from a
range of road input simulations. In the conclusion, a comparison of
active suspension fuzzy control and Proportional Integration
derivative (PID) control is shown using MATLAB simulations.
Abstract: In this paper by using the port-controlled Hamiltonian
(PCH) systems theory, a full-order nonlinear controlled model is first
developed. Then a nonlinear passivity-based robust adaptive control
(PBRAC) of switched reluctance motor in the presence of external
disturbances for the purpose of torque ripple reduction and
characteristic improvement is presented. The proposed controller
design is separated into the inner loop and the outer loop controller.
In the inner loop, passivity-based control is employed by using
energy shaping techniques to produce the proper switching function.
The outer loop control is employed by robust adaptive controller to
determine the appropriate Torque command. It can also overcome the
inherent nonlinear characteristics of the system and make the whole
system robust to uncertainties and bounded disturbances. A 4KW 8/6
SRM with experimental characteristics that takes magnetic saturation
into account is modeled, simulation results show that the proposed
scheme has good performance and practical application prospects.
Abstract: As product life cycle becomes less and less every day,
having flexible manufacturing processes for any companies seems more demanding. In the assembling of closures, i.e. opening parts in
car body, hemming process is the one which needs more attention. This paper focused on the robot roller hemming process and how to
reduce its cycle time by introducing a fast roller hemming process. A
robot roller hemming process of a tailgate of Saab 93 SportCombi
model is investigated as a case study in this paper. By applying task
separation, robot coordination, and robot cell configuration principles in the roller hemming process, three alternatives are
proposed, developed, and remarkable reduction in cycle times achieved [1].
Abstract: Indigenous Knowledge (IK) has many social and
economic benefits. However, IK is at the risk of extinction due to the
difficulties to preserve it as most of the IK largely remains
undocumented. This study aims to design a model of the factors
affecting the adoption of Information and Communication
Technologies (ICTs) for the preservation of IK. The proposed model
is based on theoretical frameworks on ICT adoption. It was designed
following a literature review of ICT adoption theories for households,
and of the factors affecting ICT adoption for IK. The theory that
fitted to the best all factors was then chosen as the basis for the
proposed model. This study found that the Model of Adoption of
Technology in Households (MATH) is the most suitable theoretical
framework for modeling ICT adoption factors for the preservation of
IK.
Abstract: In this paper the Differential Quadrature Method (DQM) is employed to study the coupled lateral-torsional free vibration behavior of the laminated composite beams. In such structures due to the fiber orientations in various layers, the lateral displacement leads to a twisting moment. The coupling of lateral and torsional vibrations is modeled by the bending-twisting material coupling rigidity. In the present study, in addition to the material coupling, the effects of shear deformation and rotary inertia are taken into account in the definition of the potential and kinetic energies of the beam. The governing differential equations of motion which form a system of three coupled PDEs are solved numerically using DQ procedure under different boundary conditions consist of the combinations of simply, clamped, free and other end conditions. The resulting natural frequencies and mode shapes for cantilever beam are compared with similar results in the literature and good agreement is achieved.
Abstract: The objective of this research seeks to transmit a distance training model to the community in the upper northeastern region. The group sampling consists of 60 community leaders in the municipality of sub-district Kumphawapi, Kumphawapi Disrict, Udonthani Province. The research tools rely on the following instruments, they are : 1) the achievement test of community leaders- training and 2) the satisfaction questionnaires of community leaders. The statistics used in data analysis takes the statistical mean, percentage, standard deviation, and statistical T-test. The resulted findings reveal : 1) the efficiency of the distance training developed by the researcher for the community leaders joining in the training received the average score between in-training and post-training period higher than the setup criterion, 2) the two groups of participants in the training achieved higher knowledge than their pre-training state, 3) the comparison of the achievements between the two group presented no different results, 4) the community leaders obtained the high-to-highest satisfaction.
Abstract: The vibrations produced by a single point defect on
various parts of the bearing under constant radial load are predicted
by using a theoretical model. The model includes variation in the
response due to the effect of bearing dimensions, rotating frequency
distribution of load. The excitation forces are generated when the
defects on the races strike to rolling elements. In case of the outer
ring defect, the pulses generated are with periodicity of outer ring
defect frequency where as for inner ring defect, the pulses are with
periodicity of inner ring defect frequency. The effort has been carried
out in preparing the physical model of the system. Different defect
frequencies are obtained and are used to find out the amplitudes of
the vibration due to excitation of the bearing parts. Increase in the
radial load or severity of the defect produces a significant change in
bearing signature characteristics.
Abstract: A Variable Structure Model Reference Adaptive Controller using state variables is proposed for a class of multi input-multi output systems. Adaptation law is of variable structure type and switching functions is designed based on stability requirements. Global exponential stability is proved based on Lyapunov criterion. Transient behavior is analyzed using sliding mode control and shows perfect model following at a finite time.
Abstract: Successful public-private-partnership (PPP)
implementation can not be achieved without the active participation of
private sector companies. This paper examines the decision-making of
private sector companies in public works delivered by the PPP model
on the basis of social responsibility theory. It proposes that private
sector companies should indentify objectives of entering into PPP
projects, and shoulder relevant social responsibilities, while a
minimum return should also be guaranteed in their favor, so as to
compensate for their assumed risk and support them to take on
responsibilities in the future. The paper also gives a calculation
regarding the appropriate scale and reasonable degree of private sector
involvement in PPP projects through the cost-benefit analysis in a
specific case study, with the purpose to guide the private sector
companies to create a cooperation environment resembling
“symbiosis" and facilitate the smooth implementation of public works
delivered by the PPP model.
Abstract: This paper describes a probabilistic method for
three-dimensional object recognition using a shared pool of surface
signatures. This technique uses flatness, orientation, and convexity
signatures that encode the surface of a free-form object into three
discriminative vectors, and then creates a shared pool of data by
clustering the signatures using a distance function. This method
applies the Bayes-s rule for recognition process, and it is extensible
to a large collection of three-dimensional objects.
Abstract: This paper presents part of a research into the small
scale modelling of masonry. Small scale testing of masonry has been
carried out by many authors, but few have attempted a systematic
determination of the parameters that affect masonry at a small scale.
The effect of increasing mortar strength and different sand gradings
under compression were investigated. The results show masonry
strength at small scale is influenced by increasing mortar strength and
different sand gradings.
Abstract: Polymer melt compressibility and mold surface roughness, which are generally ignored during the filling stage of the conventional injection molding, may become increasingly significant in micro injection molding where the parts become smaller. By employing the 2.5D generalized Hele-Shaw model, we presented here the effects of polymer compressibility and mold surface roughness on mold-filling in a micro-thickness cavity. To elucidate the effects of surface roughness, numerical investigations were conducted using a cavity flat plate which has two halves with different surface roughness. This allows the comparison of flow field on two different halves under identical processing conditions but with different roughness. Results show that polymer compressibility and mold surface roughness have effects on mold filling in micro injection molding. There is in shrinkage reduction as the density is increased due to polymer melt compressibility during the filling stage.
Abstract: Small signal stability causes small perturbations in the
generator that can cause instability in the power network. It is
generally known that small signal stability are directly related to the
generator and load properties. This paper examines the effects of
generator input variations on power system oscillations for a small
signal stability study. Eigenvaules and eigenvectors are used to
examine the stability of the power system. The dynamic power
system's mathematical model is constructed and thus calculated using
load flow and small signal stability toolbox on MATLAB. The power
system model is based on a 3-machine 9-bus system that was
modified to suit this study. In this paper, Participation Factors are a
means to gauge the effects of variation in generation with other
parameters on the network are also incorporated.
Abstract: Ground-level tropospheric ozone is one of the air
pollutants of most concern. It is mainly produced by photochemical
processes involving nitrogen oxides and volatile organic compounds
in the lower parts of the atmosphere. Ozone levels become
particularly high in regions close to high ozone precursor emissions
and during summer, when stagnant meteorological conditions with
high insolation and high temperatures are common.
In this work, some results of a study about urban ozone
distribution patterns in the city of Badajoz, which is the largest and
most industrialized city in Extremadura region (southwest Spain) are
shown. Fourteen sampling campaigns, at least one per month, were
carried out to measure ambient air ozone concentrations, during
periods that were selected according to favourable conditions to
ozone production, using an automatic portable analyzer.
Later, to evaluate the ozone distribution at the city, the measured
ozone data were analyzed using geostatistical techniques. Thus, first,
during the exploratory analysis of data, it was revealed that they were
distributed normally, which is a desirable property for the subsequent
stages of the geostatistical study. Secondly, during the structural
analysis of data, theoretical spherical models provided the best fit for
all monthly experimental variograms. The parameters of these
variograms (sill, range and nugget) revealed that the maximum
distance of spatial dependence is between 302-790 m and the
variable, air ozone concentration, is not evenly distributed in reduced
distances. Finally, predictive ozone maps were derived for all points
of the experimental study area, by use of geostatistical algorithms
(kriging). High prediction accuracy was obtained in all cases as
cross-validation showed. Useful information for hazard assessment
was also provided when probability maps, based on kriging
interpolation and kriging standard deviation, were produced.
Abstract: This paper presents the approach to design the Auto-
Tuning PID controller for interactive Water Level Process using
integral step response. The Integral Step Response (ISR) is the
method to model a dynamic process which can be done easily,
conveniently and very efficiently. Therefore this method is advantage
for design the auto tune PID controller. Our scheme uses the root
locus technique to design PID controller. In this paper MATLAB is
used for modeling and testing of the control system. The
experimental results of the interacting water level process can be
satisfyingly illustrated the transient response and the steady state
response.