Abstract: In this paper, a new algorithm for generating codebook is proposed for vector quantization (VQ) in image coding. The significant features of the training image vectors are extracted by using the proposed Orthogonal Polynomials based transformation. We propose to generate the codebook by partitioning these feature vectors into a binary tree. Each feature vector at a non-terminal node of the binary tree is directed to one of the two descendants by comparing a single feature associated with that node to a threshold. The binary tree codebook is used for encoding and decoding the feature vectors. In the decoding process the feature vectors are subjected to inverse transformation with the help of basis functions of the proposed Orthogonal Polynomials based transformation to get back the approximated input image training vectors. The results of the proposed coding are compared with the VQ using Discrete Cosine Transform (DCT) and Pairwise Nearest Neighbor (PNN) algorithm. The new algorithm results in a considerable reduction in computation time and provides better reconstructed picture quality.
Abstract: The aim of this work is to determine the supersonic
nozzle profiles used in propulsion, for the launchers or embarked
with the satellites. This design has as a role firstly, to give a
important propulsion, i.e. with uniform and parallel flow at exit,
secondly to find a short length profiles without modification of the
flow in the nozzle. The first elaborate program is used to determine
the profile of divergent by using the characteristics method for an
axisymmetric flow. The second program is conceived by using the
finite volume method to determine and test the profile found
connected to a convergent.
Abstract: Sustainable development is highly dependent on the
implementation of environmental education programs, which has as
its ultimate goal to produce environmentally literate citizens that
undertake environmentally friendly actions. Efforts on environmental
education along past years are now perceived on the increase of
citizens awareness on European countries and, particularly, in
Portugal. However, we still have a lack of information on the
prevalence of specific behaviors that contributes to sustainability,
influenced by a new attitude toward the environment. The
determination of pro-environmental behaviors prevalence in higher
education students is an important approach to understand to which
extend the next leading generation is, in practice, committed with the
goals of sustainable development. Therefore, present study evaluates
the prevalence of a specific set of behaviors (water savings, energy
savings, environmental criteria on shopping, and mobility) on the
University of Madeira students and discusses their commitment with
sustainable development.
Abstract: The objective of this study was to develop and compare alternative prediction equations of lean meat proportion (LMP) of lamb carcasses. Forty (40) male lambs, 22 of Churra Galega Bragançana Portuguese local breed and 18 of Suffolk breed were used. Lambs were slaughtered, and carcasses weighed approximately 30 min later in order to obtain hot carcass weight (HCW). After cooling at 4º C for 24-h a set of seventeen carcass measurements was recorded. The left side of carcasses was dissected into muscle, subcutaneous fat, inter-muscular fat, bone, and remainder (major blood vessels, ligaments, tendons, and thick connective tissue sheets associated with muscles), and the LMP was evaluated as the dissected muscle percentage. Prediction equations of LMP were developed, and fitting quality was evaluated through the coefficient of determination of estimation (R2 e) and standard error of estimate (SEE). Models validation was performed by k-fold crossvalidation and the coefficient of determination of prediction (R2 p) and standard error of prediction (SEP) were computed. The BT2 measurement was the best single predictor and accounted for 37.8% of the LMP variation with a SEP of 2.30%. The prediction of LMP of lamb carcasses can be based simple models, using as predictors the HCW and one fat thickness measurement.
Abstract: Students in high education are presented with new terms and concepts in nearly every lecture they attend. Many of them prefer Web-based self-tests for evaluation of their concepts understanding since they can use those tests independently of tutors- working hours and thus avoid the necessity of being in a particular place at a particular time. There is a large number of multiple-choice tests in almost every subject designed to contribute to higher level learning or discover misconceptions. Every single test provides immediate feedback to a student about the outcome of that test. In some cases a supporting system displays an overall score in case a test is taken several times by a student. What we still find missing is how to secure delivering of personalized feedback to a user while taking into consideration the user-s progress. The present work is motivated to throw some light on that question.
Abstract: Linear approximation of point spread function (PSF) is a new method for determining subpixel translations between images. The problem with the actual algorithm is the inability of determining translations larger than 1 pixel. In this paper a multiresolution technique is proposed to deal with the problem. Its performance is evaluated by comparison with two other well known registration method. In the proposed technique the images are downsampled in order to have a wider view. Progressively decreasing the downsampling rate up to the initial resolution and using linear approximation technique at each step, the algorithm is able to determine translations of several pixels in subpixel levels.
Abstract: The performance of a sucrose-based H2 production in
a completely stirred tank reactor (CSTR) was modeled by neural
network back-propagation (BP) algorithm. The H2 production was
monitored over a period of 450 days at 35±1 ºC. The proposed model
predicts H2 production rates based on hydraulic retention time
(HRT), recycle ratio, sucrose concentration and degradation, biomass
concentrations, pH, alkalinity, oxidation-reduction potential (ORP),
acids and alcohols concentrations. Artificial neural networks (ANNs)
have an ability to capture non-linear information very efficiently. In
this study, a predictive controller was proposed for management and
operation of large scale H2-fermenting systems. The relevant control
strategies can be activated by this method. BP based ANNs modeling
results was very successful and an excellent match was obtained
between the measured and the predicted rates. The efficient H2
production and system control can be provided by predictive control
method combined with the robust BP based ANN modeling tool.
Abstract: The study investigates the causal link between trade
openness and economic growth for four South Asian countries for
period 1972-1985 and 1986-2007 to examine the scenario before and
after the implementation of SAARC. Panel cointegration and
FMOLS techniques are employed for short run and long run
estimates. In 1972-85 short run unidirectional causality from GDP to
openness is found whereas, in 1986-2007 there exists bi-directional
causality between GDP and openness. The long run elasticity
magnitude between GDP and openness contains negative sign in
1972-85 which shows that there exists long run negative relationship.
While in time period 1986-2007 the elasticity magnitude has positive
sign that indicates positive causation between GDP and openness. So
it can be concluded that after the implementation of SAARC overall
situation of selected countries got better. Also long run coefficient of
error term suggests that short term equilibrium adjustments are driven
by adjustment back to long run equilibrium.
Abstract: This research attempts to study the feasibility of
augmenting an augmented reality (AR) image card on a Quick
Response (QR) code. The authors have developed a new visual tag,
which contains a QR code and an augmented AR image card. The new
visual tag has features of reading both of the revealed data of the QR
code and the instant data from the AR image card. Furthermore, a
handheld communicating device is used to read and decode the new
visual tag, and then the concealed data of the new visual tag can be
revealed and read through its visual display. In general, the QR code is
designed to store the corresponding data or, as a key, to access the
corresponding data from the server through internet. Those reveled
data from the QR code are represented in text. Normally, the AR
image card is designed to store the corresponding data in
3-Dimensional or animation/video forms. By using QR code's
property of high fault tolerant rate, the new visual tag can access those
two different types of data by using a handheld communicating device.
The new visual tag has an advantage of carrying much more data than
independent QR code or AR image card. The major findings of this
research are: 1) the most efficient area for the designed augmented AR
card augmenting on the QR code is 9% coverage area out of the total
new visual tag-s area, and 2) the best location for the augmented AR
image card augmenting on the QR code is located in the bottom-right
corner of the new visual tag.
Abstract: In this paper a fast motion estimation method for
H.264/AVC named Triplet Search Motion Estimation (TS-ME) is
proposed. Similar to some of the traditional fast motion estimation
methods and their improved proposals which restrict the search points
only to some selected candidates to decrease the computation
complexity, proposed algorithm separate the motion search process to
several steps but with some new features. First, proposed algorithm try
to search the real motion area using proposed triplet patterns instead of
some selected search points to avoid dropping into the local minimum.
Then, in the localized motion area a novel 3-step motion search
algorithm is performed. Proposed search patterns are categorized into
three rings on the basis of the distance from the search center. These
three rings are adaptively selected by referencing the surrounding
motion vectors to early terminate the motion search process. On the
other hand, computation reduction for sub pixel motion search is also
discussed considering the appearance probability of the sub pixel
motion vector. From the simulation results, motion estimation speed
improved by a factor of up to 38 when using proposed algorithm than
that of the reference software of H.264/AVC with ignorable picture
quality loss.
Abstract: The colors of the human skin represent a special
category of colors, because they are distinctive from the colors of
other natural objects. This category is found as a cluster in color
spaces, and the skin color variations between people are mostly due
to differences in the intensity. Besides, the face detection based on
skin color detection is a faster method as compared to other
techniques. In this work, we present a system to track faces by
carrying out skin color detection in four different color spaces: HSI,
YCbCr, YES and RGB. Once some skin color regions have been
detected for each color space, we label each and get some
characteristics such as size and position. We are supposing that a face
is located in one the detected regions. Next, we compare and employ
a polling strategy between labeled regions to determine the final
region where the face effectively has been detected and located.
Abstract: Double-diffusive natural convection in an open top
square cavity and heated from the side is studied numerically.
Constant temperatures and concentration are imposed along the right
and left walls while the heat balance at the surface is assumed to obey
Newton-s law of cooling. The finite difference method is used to
solve the dimensionless governing equations. The numerical results
are reported for the effect of Marangoni number, Biot number and
Prandtl number on the contours of streamlines, temperature and
concentration. The predicted results for the average Nusselt number
and Sherwood number are presented for various parametric
conditions. The parameters involved are as follows; the thermal
Marangoni number, 0 ≤ MaT ≤1000 , the solutal Marangoni number,
0 1000 c ≤ Ma ≤ , the Biot number, 0 ≤ Bi ≤ 6 , Grashof number,
5 Gr = 10 and aspect ratio 1. The study focused on both flows; thermal
dominated, N = 0.8 , and compositional dominated, N = 1.3 .
Abstract: Carbon nanotubes (CNTs) possess unique structural,
mechanical, thermal and electronic properties, and have been
proposed to be used for applications in many fields. However, to
reach the full potential of the CNTs, many problems still need to be
solved, including the development of an easy and effective
purification procedure, since synthesized CNTs contain impurities,
such as amorphous carbon, carbon nanoparticles and metal particles.
Different purification methods yield different CNT characteristics
and may be suitable for the production of different types of CNTs. In
this study, the effect of different purification chemicals on carbon
nanotube quality was investigated. CNTs were firstly synthesized by
chemical vapor deposition (CVD) of acetylene (C2H2) on a
magnesium oxide (MgO) powder impregnated with an iron nitrate
(Fe(NO3)3·9H2O) solution. The synthesis parameters were selected
as: the synthesis temperature of 800°C, the iron content in the
precursor of 5% and the synthesis time of 30 min. The liquid phase
oxidation method was applied for the purification of the synthesized
CNT materials. Three different acid chemicals (HNO3, H2SO4, and
HCl) were used in the removal of the metal catalysts from the
synthesized CNT material to investigate the possible effects of each
acid solution to the purification step. Purification experiments were
carried out at two different temperatures (75 and 120 °C), two
different acid concentrations (3 and 6 M) and for three different time
intervals (6, 8 and 15 h). A 30% H2O2 : 3M HCl (1:1 v%) solution
was also used in the purification step to remove both the metal
catalysts and the amorphous carbon. The purifications using this
solution were performed at the temperature of 75°C for 8 hours.
Purification efficiencies at different conditions were evaluated by
thermogravimetric analysis. Thermal and electrical properties of
CNTs were also determined. It was found that the obtained electrical
conductivity values for the carbon nanotubes were typical for organic
semiconductor materials and thermal stabilities were changed
depending on the purification chemicals.
Abstract: Understanding of how and where NOx formation
occurs in industrial burner is very important for efficient and clean
operation of utility burners. Also the importance of this problem is
mainly due to its relation to the pollutants produced by more burners
used widely of gas turbine in thermal power plants and glass and steel
industry.
In this article, a numerical model of an industrial burner operating
in MILD combustion is validated with experimental data.. Then
influence of air flow rate and air temperature on combustor
temperature profiles and NOX product are investigated. In order to
modification this study reports on the effects of fuel and air dilution
(with inert gases H2O, CO2, N2), and also influence of lean-premixed
of fuel, on the temperature profiles and NOX emission.
Conservation equations of mass, momentum and energy, and
transport equations of species concentrations, turbulence, combustion
and radiation modeling in addition to NO modeling equations were
solved together to present temperature and NO distribution inside the
burner.
The results shows that dilution, cause to a reduction in value of
temperature and NOX emission, and suppresses any flame
propagation inside the furnace and made the flame inside the furnace
invisible. Dilution with H2O rather than N2 and CO2 decreases further
the value of the NOX. Also with raise of lean-premix level, local
temperature of burner and the value of NOX product are decreases
because of premixing prevents local “hot spots" within the combustor
volume that can lead to significant NOx formation. Also leanpremixing
of fuel with air cause to amount of air in reaction zone is
reach more than amount that supplied as is actually needed to burn
the fuel and this act lead to limiting NOx formation
Abstract: Design and evaluation of reciprocating compressors
should include a pulsation study. The object is to ensure that
predicted pulsation levels meet guidelines to limit vibration, shaking
forces, noise, associated pressure drops, horsepower losses and
fabrication cost and time to acceptable levels. This paper explains
procedures and recommendations to select and size pulsation
suppression devices to obtain optimum arrangement in terms of
pulsation, vibration, shaking forces, performance, reliability, safety,
operation, maintenance and commercial conditions. Model and
advanced formulations for pulsation study are presented. The effect
of the full fluid dynamic model on the prediction of pulsation waves
and resulting frequency spectrum distributions are discussed.
Advanced and optimum methods of controlling pulsations are
highlighted. Useful recommendations and guidelines for pulsation
control, piping pulsation analysis, pulsation vessel design, shaking
forces, low pressure drop orifices, pulsation study report and devices
to mitigate pulsation and shaking problems are discussed.
Abstract: Double-diffusive steady convection in a partially
porous cavity with partially permeable walls and under the combined
buoyancy effects of thermal and mass diffusion was analysed
numerically using finite volume method.
The top wall is well insulated and impermeable while the bottom
surface is partially well insulated and impermeable and partially
submitted to constant temperature T1 and concentration C1. Constant
equal temperature T2 and concentration C2 are imposed along the
vertical surfaces of the enclosure. Mass suction/injection and
injection/suction are respectively considered at the bottom of the
porous centred partition and at one of the vertical walls.
Heat and mass transfer characteristics as streamlines and average
Nusselt numbers and Sherwood numbers were discussed for different
values of buoyancy ratio, Rayleigh number, and injection/suction
coefficient.
It is especially noted that increasing the injection factor
disadvantages the exchanges in the case of the injection while the
transfer is augmented in case of suction. On the other hand, a critical
value of the buoyancy ratio was highlighted for which heat and mass
transfers are minimized.
Abstract: A new numerical method for solving the twodimensional,
steady, incompressible, viscous flow equations on a
Curvilinear staggered grid is presented in this paper. The proposed
methodology is finite difference based, but essentially takes
advantage of the best features of two well-established numerical
formulations, the finite difference and finite volume methods. Some
weaknesses of the finite difference approach are removed by
exploiting the strengths of the finite volume method. In particular,
the issue of velocity-pressure coupling is dealt with in the proposed
finite difference formulation by developing a pressure correction
equation in a manner similar to the SIMPLE approach commonly
used in finite volume formulations. However, since this is purely a
finite difference formulation, numerical approximation of fluxes is
not required. Results obtained from the present method are based on
the first-order upwind scheme for the convective terms, but the
methodology can easily be modified to accommodate higher order
differencing schemes.
Abstract: In order to study floristic and molecular classification
of common wild wheat (Triticum boeoticum Boiss.), an analysis was
conducted on populations of the Triticum boeoticum collected from
different regions of Iran. Considering all floristic compositions of
habitats, six floristic groups (syntaxa) within the populations were
identified. A high level of variation of T. boeoticum also detected
using SSR markers. Our results showed that molecular method
confirmed the grouping of floristic method. In other word, the results
from our study indicate that floristic classification are still useful,
efficient, and economic tools for characterizing the amount and
distribution of genetic variation in natural populations of T.
boeoticum. Nevertheless, molecular markers appear as useful and
complementary techniques for identification and for evaluation of
genetic diversity in studied populations.
Abstract: In this paper we present a novel technique for data
hiding in binary document images. We use the concept of entropy in
order to identify document specific least distortive areas throughout
the binary document image. The document image is treated as any
other image and the proposed method utilizes the standard document
characteristics for the embedding process. Proposed method
minimizes perceptual distortion due to embedding and allows
watermark extraction without the requirement of any side information
at the decoder end.
Abstract: A model of a system concerning one species of demersal
(inshore) fish and one of pelagic (offshore) fish undergoing fishing
restricted by marine protected areas is proposed in this paper. This
setup was based on the FISH-BE model applied to the Tabina fishery
in Zamboanga del Sur, Philippines. The components of the model
equations have been adapted from widely-accepted mechanisms in
population dynamics. The model employs Gompertz-s law of growth
and interaction on each type of protected and unprotected subpopulation.
Exchange coefficients between protected and unprotected
areas were assumed to be proportional to the relative area of the
entry region. Fishing harvests were assumed to be proportional to
both the number of fishers and the number of unprotected fish. An
extra term was included for the pelagic population to allow for the
exchange between the unprotected area and the outside environment.
The systems were found to be bounded for all parameter values. The
equations for the steady state were unsolvable analytically but the
existence and uniqueness of non-zero steady states can be proven.
Plots also show that an MPA size yielding the maximum steady state
of the unprotected population can be found. All steady states were
found to be globally asymptotically stable for the entire range of
parameter values.