Abstract: The steady flow of a second order fluid through
constricted tube with slip velocity at wall is modeled and analyzed
theoretically. The governing equations are simplified by implying no
slip in radial direction. Based on Karman Pohlhausen procedure
polynomial solution for axial velocity profile is presented.
Expressions for pressure gradient, shear stress, separation and
reattachment points, and radial velocity are also calculated. The
effect of slip and no slip velocity on magnitude velocity, shear stress,
and pressure gradient are discussed and depicted graphically. It is
noted that when Reynolds number increases magnitude velocity of
the fluid decreases in both slip and no slip conditions. It is also found
that the wall shear stress, separation, and reattachment points are
strongly affected by Reynolds number.
Abstract: In this article, we used the residual correction method
to deal with transient thermoelastic problems with a hollow spherical
region when the continuum medium possesses spherically isotropic
thermoelastic properties. Based on linear thermoelastic theory, the
equations of hyperbolic heat conduction and thermoelastic motion
were combined to establish the thermoelastic dynamic model with
consideration of the deformation acceleration effect and non-Fourier
effect under the condition of transient thermal shock. The approximate
solutions of temperature and displacement distributions are obtained
using the residual correction method based on the maximum principle
in combination with the finite difference method, making it easier and
faster to obtain upper and lower approximations of exact solutions.
The proposed method is found to be an effective numerical method
with satisfactory accuracy. Moreover, the result shows that the effect
of transient thermal shock induced by deformation acceleration is
enhanced by non-Fourier heat conduction with increased peak stress.
The influence on the stress increases with the thermal relaxation time.
Abstract: The relationship dependence between RSS and distance
in an enclosed environment is an important consideration because it is
a factor that can influence the reliability of any localization algorithm
founded on RSS. Several algorithms effectively reduce the variance of
RSS to improve localization or accuracy performance. Our proposed
algorithm essentially avoids this pitfall and consequently, its high
adaptability in the face of erratic radio signal. Using 3 anchors in
close proximity of each other, we are able to establish that RSS can be
used as reliable indicator for localization with an acceptable degree of
accuracy. Inherent in this concept, is the ability for each prospective
anchor to validate (guarantee) the position or the proximity of the
other 2 anchors involved in the localization and vice versa. This
procedure ensures that the uncertainties of radio signals due to
multipath effects in enclosed environments are minimized. A major
driver of this idea is the implicit topological relationship among
sensors due to raw radio signal strength. The algorithm is an area
based algorithm; however, it does not trade accuracy for precision
(i.e the size of the returned area).
Abstract: Household waste form a larger proportion of waste
generated across the state, accumulation of organic waste is an
apparent problem and the existing dump sites could be overstress.
Niger state has abundant arable land and water resources thus should
be one of the highest producers of agricultural crops in the country.
However, the major challenge to agricultural sector today is loss of
soil nutrient coupled with high cost of fertilizer. These have
continued to increase the use of fertilizer and decomposed solid waste
for enhance agricultural yield, which have varying effects on the soil
as well a threat to human livelihood. Consequently, vegetable yield
samples from poultry droppings, decomposed household waste
manure, NPK treatments and control from each replication were
subjected to proximate analysis to determine the nutritional and antinutritional
component as well as heavy metal concentration. Data
collected was analyzed using SPSS software and Randomized
complete Block Design means were compared. The result shows that
the treatments do not devoid the concentrations of any nutritional
components while the anti-nutritional analysis proved that NPK had
higher oxalate content than control and organic treats. The
concentration of lead and cadmium are within safe permissible level
while the mercury level exceeded the FAO/WHO maximum
permissible limit for the entire treatments depicts the need for urgent
intervention to minimize mercury levels in soil and manure in order
to mitigate its toxic effect. Thus, eco-agriculture should be widely
accepted and promoted by the stakeholders for soil amendment,
higher yield, strategies for sustainable environmental protection, food
security, poverty eradication, attainment of sustainable development
and healthy livelihood.
Abstract: This work deals with the problem of MHD mixed
convection in a completely porous and differentially heated vertical
channel. The model of Darcy-Brinkman-Forchheimer with the
Boussinesq approximation is adopted and the governing equations are
solved by the finite volume method. The effects of magnetic field and
buoyancy force intensities are given by the Hartmann and Richardson
numbers respectively, as well as the Joule heating represented by
Eckert number on the velocity and temperature fields, are examined.
The main results show an augmentation of heat transfer rate with the
decrease of Darcy number and the increase of Ri and Ha when Joule
heating is neglected.
Abstract: This paper describes a sliding mode controller for
autonomous underwater vehicles (AUVs). The dynamic of AUV
model is highly nonlinear because of many factors, such as
hydrodynamic drag, damping, and lift forces, Coriolis and centripetal
forces, gravity and buoyancy forces, as well as forces from thruster.
To address these difficulties, a nonlinear sliding mode controller is
designed to approximate the nonlinear dynamics of AUV and
improve trajectory tracking. Moreover, the proposed controller can
profoundly attenuate the effects of uncertainties and external
disturbances in the closed-loop system. Using the Lyapunov theory
the boundedness of AUV tracking errors and the stability of the
proposed control system are also guaranteed. Numerical simulation
studies of an AUV are included to illustrate the effectiveness of the
presented approach.
Abstract: Massive rock avalanches formed some of the largest landslide deposits on Earth and they represent one of the major geohazards in high-relief mountains. This paper interprets a very large sedimentary fan (the Sernio fan, Valtellina, Northern Italy), located 20 Km SW from Val Pola Rock avalanche (1987), as the deposit of a partial collapse of a Deep Seated Gravitational Slope Deformation (DSGSD), afterwards eroded and buried by debris flows. The proposed emplacement sequence has been reconstructed based on geomorphological, structural and mechanical evidences. The Sernio fan is actually considered anomalous with reference to the very high ratio between the fan area (≈ 4.5km2) and the basin area (≈ 3km2). The morphology of the fan area is characterised by steep slopes (dip ≈ 20%) and the fan apex is extended for 1.8 km inside the small catchment basin. This sedimentary fan was originated by a landslide that interested a part of a large deep-seated gravitational slope deformation, involving a wide area of about 55 km². The main controlling factor is tectonic and it is related to the proximity to regional fault systems and the consequent occurrence of fault weak rocks (GSI locally lower than 10 with compressive stress lower than 20MPa). Moreover, the fan deposit shows sedimentary evidences of recent debris flow events. The best current explanation of the Sernio fan involves an initial failure of some hundreds of Mm3. The run-out was quite limited because of the morphology of Valtellina’s valley floor, and the deposit filled the main valley forming a landslide dam, as confirmed by the lacustrine deposits detected upstream the fan. Nowadays the debris flow events represent the main hazard in the study area.
Abstract: The purpose of this research was to investigate the
creep behaviour of the heterogeneous Timber-UHPFRC beams. New
developments have been done to further improve the structural
performance, such as strengthening of the timber (glulam) beam by
bonding composite material combine with an ultra-high performance
fibre reinforced concrete (UHPFRC) internally reinforced with or
without carbon fibre reinforced polymer (CFRP) bars. However, in
the design of wooden structures, in addition to the criteria of
strengthening and stiffness, deformability due to the creep of wood,
especially in horizontal elements, is also a design criterion. Glulam,
UHPFRC and CFRP may be an interesting composite mix to respond
to the issue of creep behaviour of composite structures made of
different materials with different rheological properties. In this paper,
we describe an experimental and analytical investigation of the creep
performance of the glulam-UHPFRC-CFRP beams assembled by
bonding. The experimental investigations creep behaviour was
conducted for different environments: in- and outside under constant
loading for approximately a year. The measured results are compared
with numerical ones obtained by an analytical model. This model was
developed to predict the creep response of the glulam-UHPFRCCFRP
beams based on the creep characteristics of the individual
components. The results show that heterogeneous glulam-UHPFRC
beams provide an improvement in both the strengthening and
stiffness, and can also effectively reduce the creep deflection of
wooden beams.
Abstract: Hollow section for bridge columns has some
advantages. However, current seismic design codes do not provide
design regulations for hollow bridge piers. There have been many
experimental studied for hollow reinforced concrete piers in the world.
But, Study for hollow section for bridge piers in Korea has been begun
with approximately 2000s. There has been conducted experimental
study for hollow piers of flexural controlled sections by Yeungnam
University, Sung kyunkwan University, Korea Expressway
Corporation in 2009. This study concluded that flexural controlled
sections for hollow piers showed the similar behavior to solid sections.
And there have been conducted experimental study for hollow piers of
compression controlled sections by Yeungnam University, Korea
Institute of Construction Technology in 2012. This study concluded
that compression controlled sections for hollow piers showed
compression fracture of concrete in inside wall face. Samsung
Construction & Trading Corporation has been conducted study with
Yeungnam University for reduce the quantity of reinforcement details
about hollow piers. Reduce the quantity of reinforcement details are
triangular cross tie. This study concluded that triangular reinforcement
details showed the similar behavior as compared with existing
reinforcement details.
Abstract: In most existing buildings in hot climate, cooling
loads lead to high primary energy consumption and consequently
high CO2 emissions. These can be substantially decreased with
integrated renewable energy systems. Kuwait is characterized by its
dry hot long summer and short warm winter. Kuwait receives annual
total radiation more than 5280 MJ/m2 with approximately 3347 h of
sunshine. Solar energy systems consist of PV modules and parabolic
trough collectors are considered to satisfy electricity consumption,
domestic water heating, and cooling loads of an existing building.
This paper presents the results of an extensive program of energy
conservation and energy generation using integrated photovoltaic
(PV) modules and Parabolic Trough Collectors (PTC). The program
conducted on an existing institutional building intending to convert it
into a Net-Zero Energy Building (NZEB) or near net Zero Energy
Building (nNZEB). The program consists of two phases; the first
phase is concerned with energy auditing and energy conservation
measures at minimum cost and the second phase considers the
installation of photovoltaic modules and parabolic trough collectors.
The 2-storey building under consideration is the Applied Sciences
Department at the College of Technological Studies, Kuwait. Single
effect lithium bromide water absorption chillers are implemented to
provide air conditioning load to the building. A numerical model is
developed to evaluate the performance of parabolic trough collectors
in Kuwait climate. Transient simulation program (TRNSYS) is
adapted to simulate the performance of different solar system
components. In addition, a numerical model is developed to assess
the environmental impacts of building integrated renewable energy
systems. Results indicate that efficient energy conservation can play
an important role in converting the existing buildings into NZEBs as
it saves a significant portion of annual energy consumption of the
building. The first phase results in an energy conservation of about
28% of the building consumption. In the second phase, the integrated
PV completely covers the lighting and equipment loads of the
building. On the other hand, parabolic trough collectors of optimum
area of 765 m2 can satisfy a significant portion of the cooling load,
i.e about73% of the total building cooling load. The annual avoided
CO2 emission is evaluated at the optimum conditions to assess the
environmental impacts of renewable energy systems. The total annual
avoided CO2 emission is about 680 metric ton/year which confirms
the environmental impacts of these systems in Kuwait.
Abstract: In some applications, such as image recognition or
compression, segmentation refers to the process of partitioning a
digital image into multiple segments. Image segmentation is typically
used to locate objects and boundaries (lines, curves, etc.) in images.
Image segmentation is to classify or cluster an image into several
parts (regions) according to the feature of image, for example, the
pixel value or the frequency response. More precisely, image
segmentation is the process of assigning a label to every pixel in an
image such that pixels with the same label share certain visual
characteristics. The result of image segmentation is a set of segments
that collectively cover the entire image, or a set of contours extracted
from the image. Several image segmentation algorithms were
proposed to segment an image before recognition or compression. Up
to now, many image segmentation algorithms exist and be
extensively applied in science and daily life. According to their
segmentation method, we can approximately categorize them into
region-based segmentation, data clustering, and edge-base
segmentation. In this paper, we give a study of several popular image
segmentation algorithms that are available.
Abstract: In this paper, the notion of rank−k numerical range
of rectangular complex matrix polynomials are introduced. Some
algebraic and geometrical properties are investigated. Moreover, for
Є > 0, the notion of Birkhoff-James approximate orthogonality
sets for Є−higher rank numerical ranges of rectangular matrix
polynomials is also introduced and studied. The proposed definitions
yield a natural generalization of the standard higher rank numerical
ranges.
Abstract: This study discusses a Turkish music education model
similar to its Venezuelan counterpart El Sistema, in which
socialization and human development are the main goals. The Music
for Peace (Baris Icin Muzik) model, founded in 2005 by an idealist
humanitarian in Istanbul, started as a pilot project with accordion and
today makes symphonic music education. The program aims to offer
social change through free-of-charge. In such a big city like Istanbul, in a deprived inner city center
people have poor economic, social and cultural conditions. In that
Edirnekapi district people don’t have opportunities to join the cultural
and social life, like music or sports. It is believed that this initiative
covered a part of this gap by giving children the opportunities to
participate in social and cultural life. In this study it is planned to understand what social changes could
music education could make in children’s lives. In the complimentary
music lessons children works in groups, which helps them to learn
the feelings of solidarity, friendship, communion and sharing. By Music for Peace project children connect with the community,
they have the belief to succeed in life because they feel that they are
loved by their friends, instructors and families. In short they feel that
they are important, thus brings the success in life. Additionally, it is
believed that, this program has achieved success. Today
approximately 400 children participate in this programs orchestras
and choirs. Some of the students get into the conservatories. And the
center is not just a place where they get music lessons but also a place
where they get socialized. And music education helps children to
have strong sense of identity, self-confidence and self-esteem.
Abstract: The paper presents an advanced control system for
tennis ball throwing machines to improve their accuracy according to
the ball impact points. A further advantage of the system is the much
easier calibration process involving the intelligent solution of the
automatic adjustment of the stroking parameters according to the ball
elasticity, the self-calibration, the use of the safety margin at very flat
strokes and the possibility to placing the machine to any position of
the half court. The system applies mathematical methods to
determine the exact ball trajectories and special approximating
processes to access all points on the aimed half court.
Abstract: In this article, we deal with a variant of the classical
course timetabling problem that has a practical application in many
areas of education. In particular, in this paper we are interested in
high schools remedial courses. The purpose of such courses is to
provide under-prepared students with the skills necessary to succeed
in their studies. In particular, a student might be under prepared in
an entire course, or only in a part of it. The limited availability
of funds, as well as the limited amount of time and teachers at
disposal, often requires schools to choose which courses and/or which
teaching units to activate. Thus, schools need to model the training
offer and the related timetabling, with the goal of ensuring the
highest possible teaching quality, by meeting the above-mentioned
financial, time and resources constraints. Moreover, there are some
prerequisites between the teaching units that must be satisfied. We
first present a Mixed-Integer Programming (MIP) model to solve
this problem to optimality. However, the presence of many peculiar
constraints contributes inevitably in increasing the complexity of
the mathematical model. Thus, solving it through a general-purpose
solver may be performed for small instances only, while solving
real-life-sized instances of such model requires specific techniques
or heuristic approaches. For this purpose, we also propose a heuristic
approach, in which we make use of a fast constructive procedure
to obtain a feasible solution. To assess our exact and heuristic
approaches we perform extensive computational results on both
real-life instances (obtained from a high school in Lecce, Italy) and
randomly generated instances. Our tests show that the MIP model is
never solved to optimality, with an average optimality gap of 57%.
On the other hand, the heuristic algorithm is much faster (in about the
50% of the considered instances it converges in approximately half of
the time limit) and in many cases allows achieving an improvement
on the objective function value obtained by the MIP model. Such an
improvement ranges between 18% and 66%.
Abstract: The present study applies the inverse method and
three-dimensional CFD commercial software in conjunction with the
experimental temperature data to investigate the heat transfer and fluid
flow characteristics of the plate-fin heat sink in a rectangular closed
enclosure. The inverse method with the finite difference method and
the experimental temperature data is applied to determine the
approximate heat transfer coefficient. Later, based on the obtained
results, the zero-equation turbulence model is used to obtain the heat
transfer and fluid flow characteristics between two fins. T0 validate
the accuracy of the results obtained, the comparison of the heat transfer
coefficient is made. The obtained temperature at selected
measurement locations of the fin is also compared with experimental
data. The effect of the height of the rectangular enclosure on the
obtained results is discussed.
Abstract: An approach was evaluated for the retrieval of soil
moisture of bare soil surface using bistatic scatterometer data in the
angular range of 200 to 700 at VV- and HH- polarization. The
microwave data was acquired by specially designed X-band (10
GHz) bistatic scatterometer. The linear regression analysis was done
between scattering coefficients and soil moisture content to select the
suitable incidence angle for retrieval of soil moisture content. The 250
incidence angle was found more suitable. The support vector
regression analysis was used to approximate the function described
by the input output relationship between the scattering coefficient and
corresponding measured values of the soil moisture content. The
performance of support vector regression algorithm was evaluated by
comparing the observed and the estimated soil moisture content by
statistical performance indices %Bias, root mean squared error
(RMSE) and Nash-Sutcliffe Efficiency (NSE). The values of %Bias,
root mean squared error (RMSE) and Nash-Sutcliffe Efficiency
(NSE) were found 2.9451, 1.0986 and 0.9214 respectively at HHpolarization.
At VV- polarization, the values of %Bias, root mean
squared error (RMSE) and Nash-Sutcliffe Efficiency (NSE) were
found 3.6186, 0.9373 and 0.9428 respectively.
Abstract: The purpose of this study is the discrimination of 28
postmenopausal with osteoporotic femoral fractures from an agematched
control group of 28 women using texture analysis based on
fractals. Two pre-processing approaches are applied on radiographic
images; these techniques are compared to highlight the choice of the
pre-processing method. Furthermore, the values of the fractal
dimension are compared to those of the fractal signature in terms of
the classification of the two populations. In a second analysis, the
BMD measure at proximal femur was compared to the fractal
analysis, the latter, which is a non-invasive technique, allowed a
better discrimination; the results confirm that the fractal analysis of
texture on calcaneus radiographs is able to discriminate osteoporotic
patients with femoral fracture from controls. This discrimination was
efficient compared to that obtained by BMD alone. It was also
present in comparing subgroups with overlapping values of BMD.
Abstract: DNA Barcode provides good sources of needed
information to classify living species. The classification problem has
to be supported with reliable methods and algorithms. To analyze
species regions or entire genomes, it becomes necessary to use the
similarity sequence methods. A large set of sequences can be
simultaneously compared using Multiple Sequence Alignment which
is known to be NP-complete. However, all the used methods are still
computationally very expensive and require significant computational
infrastructure. Our goal is to build predictive models that are highly
accurate and interpretable. In fact, our method permits to avoid the
complex problem of form and structure in different classes of
organisms. The empirical data and their classification performances
are compared with other methods. Evenly, in this study, we present
our system which is consisted of three phases. The first one, is called
transformation, is composed of three sub steps; Electron-Ion
Interaction Pseudopotential (EIIP) for the codification of DNA
Barcodes, Fourier Transform and Power Spectrum Signal Processing.
Moreover, the second phase step is an approximation; it is
empowered by the use of Multi Library Wavelet Neural Networks
(MLWNN). Finally, the third one, is called the classification of DNA
Barcodes, is realized by applying the algorithm of hierarchical
classification.
Abstract: This work presents an improved single fiber pull-out
test for fiber/matrix interface characterization. This test has been
used to study the Inter-Facial Shear Strength ‘IFSS’ of hemp fibers
reinforced polypropylene (PP). For this aim, the fiber diameter
has been carefully measured using a tomography inspired method.
The fiber section contour can then be approximated by a circle
or a polygon. The results show that the IFSS is overestimated if
the circular approximation is used. The Influence of the molding
temperature on the IFSS has also been studied. We find that a molding
temperature of 183◦C leads to better interfacial properties. Above or
below this temperature the interface strength is reduced.