Abstract: This paper presents a model predictive control (MPC)
of a utility interactive three phase inverter (TPI) for a photovoltaic
(PV) system at commercial level. The proposed model uses phase
locked loop (PLL) to synchronize the TPI with the power electric
grid (PEG) and performs MPC control in a dq reference frame. TPI
model consists of a boost converter (BC), maximum power point
tracking (MPPT) control, and a three-leg voltage source inverter
(VSI). The operational model of VSI is used to synthesize the
sinusoidal current and track the reference. The model is validated
using a 35.7 kW PV system in Matlab/Simulink. Implementation
results show simplicity and accuracy, as well as reliability of the
model.
Abstract: The health care must be a right for people around the
world, but in order to guarantee the access to all, it is necessary to
overcome geographical barriers. Telemedicine take advantage of
Information Communication Technologies to deploy health care
services around the world. To achieve those goals, it is necessary to
use existing last mile solution to create access for home users, which
is why is necessary to establish the channel characteristics for those
kinds of services. This paper presents an analysis of network
performance of last mile solution for the use of IPTV broadcasting
with the application of streaming for telemedicine apps.
Abstract: In this study, students’ learning has been investigated
and satisfaction in one of the course offered at Qatar University
Foundation Program. Innovative teaching has been implied
methodology that emphasizes on enhancing students’ thinking skills,
decision making, and problem solving skills. Some interesting results
were found which could be used to further improvement of the
teaching methodology. In Fall 2012 in Foundation Program Math
department at Qatar University has started implementing new ways
of teaching Math by introducing MyMathLab (MML) as an
innovative interactive tool in addition of the use Blackboard to
support standard teaching such as Discussion board in Virtual class to
engage students outside of classroom and to enhance independent,
active learning that promote students’ critical thinking skills, decision
making, and problem solving skills through the learning process.
Abstract: Government reports and published research have
flagged and brought to public attention the deteriorating condition of
a large percentage of bridges in Canada and the United States. With
the increasing number of deteriorated bridges in the US, Canada, and
around the globe, condition assessment techniques of concrete
bridges are evolving. Investigation for bridges’ defects such as
cracks, spalls, and delamination and their level of severity are the
main objectives of condition assessment. Inspection and
rehabilitation programs are being implemented to monitor and
maintain deteriorated bridge infrastructure. This paper highlights the
state-of-the art of current practices being performed for concrete
bridge inspection. The information is gathered from the literature and
through a distributed questionnaire. The current practices in concrete
bridge inspection rely on the use of hummer sounding and chain
dragging tests. Non-Destructive Testing (NDT) techniques are not
being utilized fully in the process. Nonetheless, they are being
partially utilized by the recommendation of the bridge inspector after
conducting visual inspection. Lanes are usually closed during the
performance of visual inspection and bridge inspection in general.
Abstract: This study, tries to suggest a design method based on
displacement using finite difference numerical modeling in
reinforcing soil retaining wall with steel strip. In this case, dynamic
loading characteristics such as duration, frequency, peak ground
acceleration, geometrical characteristics of reinforced soil structure
and type of the site are considered to correct the pseudo static method
and finally introduce the pseudo static coefficient as a function of
seismic performance level and peak ground acceleration. For this
purpose, the influence of dynamic loading characteristics,
reinforcement length, height of reinforced system and type of the site
are investigated on seismic behavior of reinforcing soil retaining wall
with steel strip. Numerical results illustrate that the seismic response
of this type of wall is highly dependent to cumulative absolute
velocity, maximum acceleration, and height and reinforcement length
so that the reinforcement length can be introduced as the main factor
in shape of failure. Considering the loading parameters, geometric parameters of the
wall and type of the site showed that the used method in this study
leads to efficient designs in comparison with other methods, which
are usually based on limit-equilibrium concept. The outputs show the
over-estimation of equilibrium design methods in comparison with
proposed displacement based methods here.
Abstract: This study focuses on the hydro-geology and chemical
constituents analysis of Ikogosi Warm Spring waters in South West
Nigeria. Ikogosi warm spring is a global tourist attraction because it
has both warm and cold spring sources. Water samples from the cold
spring, warm spring and the meeting point were collected, analyzed
and the result shows close similarity in temperature, hydrogen iron
concentration (pH), alkalinity, hardness, Calcium, Magnesium,
Sodium, Iron, total dissolved solid and heavy metals. The measured
parameters in the water samples are within World Health
Organisation standards for fresh water. The study of the geology of
the warm spring reveals that the study area is underlain by a group of
slightly migmatised to non-migmatised paraschists and meta-igneous
rocks. Also, concentration levels of selected heavy metals, (Copper,
Cadmium, Zinc, Arsenic and Cromium) were determined in the water
(ppm) samples. Chromium had the highest concentration value of
1.52ppm (an average of 49.67%) and Cadmium had the lowest
concentration with value of 0.15ppm (an average of 4.89%).
Comparison of these results showed that, their mean levels are within
the standard values obtained in Nigeria. It can be concluded that both
warm and spring water are safe for drinking.
Abstract: This paper presents an extensive review of literature
relevant to the modelling techniques adopted in sediment yield and
hydrological modelling. Several studies relating to sediment yield are
discussed. Many research areas of sedimentation in rivers, runoff and
reservoirs are presented. Different types of hydrological models,
different methods employed in selecting appropriate models for
different case studies are analysed. Applications of evolutionary
algorithms and artificial intelligence techniques are discussed and
compared especially in water resources management and modelling.
This review concentrates on Genetic Programming (GP) and fully
discusses its theories and applications. The successful applications of
GP as a soft computing technique were reviewed in sediment
modelling. Some fundamental issues such as benchmark,
generalization ability, bloat, over-fitting and other open issues
relating to the working principles of GP are highlighted. This paper
concludes with the identification of some research gaps in
hydrological modelling and sediment yield.
Abstract: The present study examined how translation teachers
develop final tests as measures for checking on the quality of
students’ academic translation in Iranian context. To achieve this
goal, thirty experienced male and female translation teachers from the
four types of the universities offering the program were invited to an
in-depth 30-minute one-session semi-structured interview. The
responses provided showed how much discrepancy exists among the
Iranian translation teachers (as developers of final translation tests),
who are least informed with the current translation evaluation
methods. It was also revealed that the criteria they use for developing
such tests and scoring student translations are not theory-driven but
are highly subjective, mainly based on their personal experience and
intuition. Hence, the quality and accountability of such tests are under
serious question. The results also confirmed that the dominant
method commonly and currently practiced is the purely essay-type
format. To remedy the situation, some suggestions are in order. As
part of the solution, to improve the reliability and validity of such
tests, the present summative, product-oriented evaluation should be
accompanied with some formative, process-oriented methods of
evaluation. Training the teachers and helping them get acquainted
with modern principles of translation evaluation as well as the
existing models, and rating scales does improve the quality of
academic translation evaluation.
Abstract: We consider the problem of stabilization of an unstable
heat equation in a 2-D, 3-D and generally n-D domain by deriving a
generalized backstepping boundary control design methodology. To
stabilize the systems, we design boundary backstepping controllers
inspired by the 1-D unstable heat equation stabilization procedure.
We assume that one side of the boundary is hinged and the other
side is controlled for each direction of the domain. Thus, controllers
act on two boundaries for 2-D domain, three boundaries for 3-D
domain and ”n” boundaries for n-D domain. The main idea of the
design is to derive ”n” controllers for each of the dimensions by
using ”n” kernel functions. Thus, we obtain ”n” controllers for the
”n” dimensional case. We use a transformation to change the system
into an exponentially stable ”n” dimensional heat equation. The
transformation used in this paper is a generalized Volterra/Fredholm
type with ”n” kernel functions for n-D domain instead of the one
kernel function of 1-D design.
Abstract: In the context of the handwriting recognition, we
propose an off line system for the recognition of the Arabic
handwritten words of the Algerian departments. The study is based
mainly on the evaluation of neural network performances, trained
with the gradient back propagation algorithm. The used parameters to
form the input vector of the neural network are extracted on the
binary images of the handwritten word by several methods. The
Distribution parameters, the centered moments of the different
projections of the different segments, the centered moments of the
word image coding according to the directions of Freeman, and the
Barr features applied binary image of the word and on its different
segments. The classification is achieved by a multi layers perceptron.
A detailed experiment is carried and satisfactory recognition results
are reported.
Abstract: The need to save time and cost of soil testing at the
planning stage of road work has necessitated developing predictive
models. This study proposes a model for predicting the dry density of
lateritic soils stabilized with corn cob ash (CCA) and blended cement
- CCA. Lateritic soil was first stabilized with CCA at 1.5, 3.0, 4.5 and
6% of the weight of soil and then stabilized with the same
proportions as replacement for cement. Dry density, specific gravity,
maximum degree of saturation and moisture content were determined
for each stabilized soil specimen, following standard procedure.
Polynomial equations containing alpha and beta parameters for CCA
and blended CCA-cement were developed. Experimental values were
correlated with the values predicted from the Matlab curve fitting
tool, and the Solver function of Microsoft Excel 2010. The correlation
coefficient (R2) of 0.86 was obtained indicating that the model could
be accepted in predicting the maximum dry density of CCA stabilized
soils to facilitate quick decision making in roadworks.
Abstract: Extreme formation is a theoretical concept of selfsustain
flight when a big airliner is followed by a small UAV glider
flying in the airliner wake vortex. The paper presents results of a
climb analysis with the goal to lift the gliding UAV to airliners cruise
altitude. Wake vortex models, the UAV drag polar and basic
parameters and airliner’s climb profile are introduced at first.
Afterwards, flight performance of the UAV in a wake vortex is
evaluated by analytical methods. Time history of optimal distance
between an airliner and the UAV during a climb is determined. The
results are encouraging. Therefore available UAV drag margin for
electricity generation is figured out for different vortex models.
Abstract: Analytical techniques for measuring and planning
railway capacity expansion activities have been considered in this
article. A preliminary mathematical framework involving track
duplication and section sub divisions is proposed for this task. In
railways, these features have a great effect on network performance
and for this reason they have been considered. Additional motivations
have also arisen from the limitations of prior models that have not
included them.
Abstract: This article presents the main results of a numerical
investigation on the uncertainty of dynamic response of structures
with statistically correlated random damping Gamma distributed. A
computational method based on a Linear Statistical Model (LSM) is
implemented to predict second order statistics for the response of a
typical industrial building structure. The significance of random
damping with correlated parameters and its implications on the
sensitivity of structural peak response in the neighborhood of a
resonant frequency are discussed in light of considerable ranges of
damping uncertainties and correlation coefficients. The results are
compared to those generated using Monte Carlo simulation
techniques. The numerical results obtained show the importance of
damping uncertainty and statistical correlation of damping
coefficients when obtaining accurate probabilistic estimates of
dynamic response of structures. Furthermore, the effectiveness of the
LSM model to efficiently predict uncertainty propagation for
structural dynamic problems with correlated damping parameters is
demonstrated.
Abstract: Modelling of building processes of a multimodal
freight transportation support information system is discussed based
on modern CASE technologies. Functional efficiencies of ports in
the eastern part of the Black Sea are analyzed taking into account
their ecological, seasonal, resource usage parameters. By resources,
we mean capacities of berths, cranes, automotive transport, as well as
work crews and neighbouring airports. For the purpose of designing
database of computer support system for Managerial (Logistics)
function, using Object-Role Modeling (ORM) tool (NORMA–Natural ORM Architecture) is proposed, after which Entity
Relationship Model (ERM) is generated in automated process.
Software is developed based on Process-Oriented and Service-Oriented architecture, in Visual Studio.NET environment.
Abstract: In the last decade the emergence of new social needs
as an effect of the economic crisis has stimulated the flourishing of
business endeavours characterised by explicit social goals. Social
start-ups, social enterprises or Corporate Social Responsibility
operations carried out by traditional companies are quintessential
examples in this regard. This paper analyses these kinds of initiatives
in order to discover the main characteristics of social business models
and to provide insights to social entrepreneurs for developing or
improving their strategies. The research is conducted through the
integration of literature review and case study analysis and, thanks to
the recognition of the importance of both profits and social impacts
as the key success factors for a social business model, proposes a
framework for identifying indicators suitable for measuring the social
impacts generated.
Abstract: The ferrites ZnFe2O4, CdFe2O4 and CuFe2O4 are
synthesized in laboratory conditions using ceramic technology. Their
homogeneity and structure are proven by X-Ray diffraction analysis
and Mössbauer spectroscopy. The synthesized ferrites are subjected
to strong acid and high temperature leaching with solutions of H2SO4,
HCl and HNO3. The results indicate that the highest degree of
leaching of Zn, Cd and Cu from the ferrites is achieved by use of
HCl. The charging of five zinc sulfide concentrates was optimized using
the criterion of minimal amount of zinc ferrite produced when
roasting the concentrates in a fluidized bed. The results obtained are
interpreted in terms of the hydrometallurgical zinc production and
maximum recovery of zinc, copper and cadmium from initial zinc
concentrates after their roasting.
Abstract: In recent years, the power system has been changed
and a flexible power pricing system such as demand response has been
sought in Japan. The demand response system works simply in the
household sector and the owner as the decision-maker, can benefit
from power saving. On the other hand, the execution of demand
response in the office building is more complex than in the household
because various people such as owners, building administrators and
occupants are involved in the decision-making process. While the
owners benefit from demand saving, the occupants are exposed to
restricted benefits of a demand-saved environment. One of the reasons
is that building systems are usually under centralized management and
each occupant cannot choose freely whether to participate in demand
response or not. In addition, it is unclear whether incentives give
occupants the motivation to participate. However, the recent
development of IT and building systems enables the personalized
control of the office environment where each occupant can control the
lighting level or temperature individually. Therefore, it can be possible
to have a system which each occupant can make a decision of whether
or not to participate in demand response in the office building. This study investigates personal responses to demand response
requests, under the condition where each occupant can adjust their
brightness individually in their workspace. Once workers participate
in the demand response, their desk-lights are automatically turned off.
The participation rates in the demand response events are compared
among four groups, which are divided by different motivation, the
presence, or absence of incentives and the method of participation. The
result shows that there are significant differences of participation rates
in demand response event between four groups. The method of
participation has a large effect on the participation rate. The “Opt-out”
groups where the occupants are automatically enrolled in a demand
response event if they do not express non-participation have the
highest participation rate in the four groups. Incentives also have an
effect on the participation rate. This study also reports on the impact of low illumination office
environment on the occupants, such as stress or fatigue. The
electrocardiogram and the questionnaire are used to investigate the
autonomic nervous activity and subjective fatigue symptoms of the
occupants. There is no big difference between dim workspace during
demand response event and bright workspace in autonomic nervous
activity and fatigue.
Abstract: In this study, we examine some spectral properties
of non-selfadjoint matrix-valued difference equations consisting of
a polynomial-type Jost solution. The aim of this study is to
investigate the eigenvalues and spectral singularities of the difference
operator L which is expressed by the above-mentioned difference
equation. Firstly, thanks to the representation of polynomial type Jost
solution of this equation, we obtain asymptotics and some analytical
properties. Then, using the uniqueness theorems of analytic functions,
we guarantee that the operator L has a finite number of eigenvalues
and spectral singularities.
Abstract: In order to be capable of dealing with uncertainties,
subjectivities, including vagueness arising in building construction
projects, the application of fuzzy reasoning technique based on fuzzy
set theory is proposed. This study contributes significantly to the
development of a fuzzy reasoning safety risk assessment model for
building construction projects that could be employed to assess the
risk magnitude of each hazardous event identified during
construction, and a third parameter of probability of consequence is
incorporated in the model. By using the proposed safety risk analysis
methodology, more reliable and less ambiguities, which provide the
safety risk management project team for decision-making purposes.