Abstract: This paper presents nonlinear pulse propagation characteristics for different input optical pulse shapes with various input pulse energy levels in semiconductor optical amplifiers. For simulation of nonlinear pulse propagation, finite-difference beam propagation method is used to solve the nonlinear Schrödinger equation. In this equation, gain spectrum dynamics, gain saturation are taken into account which depends on carrier depletion, carrier heating, spectral-hole burning, group velocity dispersion, self-phase modulation and two photon absorption. From this analysis, we obtained the output waveforms and spectra for different input pulse shapes as well as for different input energies. It shows clearly that the peak position of the output waveforms are shifted toward the leading edge which due to the gain saturation of the SOA for higher input pulse energies. We also analyzed and compared the normalized difference of full-width at half maximum for different input pulse shapes in the SOA.
Abstract: Logistics distributors face the issue of having to
provide increasing service levels while being forced to reduce costs at
the same time. Same-day delivery, quick order processing and rapidly
growing ranges of articles are only some of the prevailing challenges.
One key aspect of the performance of an intra-logistics system is how
often and in which amplitude congestions and dysfunctions affect the
processing operations. By gaining knowledge of the so called
‘performance availability’ of such a system during the planning stage,
oversizing and wasting can be reduced whereas planning
transparency is increased. State of the art for the determination of this
KPI is simulation studies. However, their structure and therefore their
results may vary unforeseeably. This article proposes a concept for
the establishment of ‘certified’ and hence reliable and comparable
simulation models.
Abstract: We present a trigonometric scheme to approximate a
circular arc with its two end points and two end tangents/unit
tangents. A rational cubic trigonometric Bézier curve is constructed
whose end control points are defined by the end points of the circular
arc. Weight functions and the remaining control points of the cubic
trigonometric Bézier curve are estimated by variational approach to
reproduce a circular arc. The radius error is calculated and found less
than the existing techniques.
Abstract: This study investigates how AlGaAs/GaAs thin film
solar cells perform under varying global solar spectrum due to the
changes of environmental parameters such as the air mass and the
atmospheric turbidity. The solar irradiance striking the solar cell is
simulated using the spectral irradiance model SMARTS2 (Simple
Model of the Atmospheric Radiative Transfer of Sunshine) for clear
skies on the site of Setif (Algeria). The results show a reduction in the
short circuit current due to increasing atmospheric turbidity, it is
63.09% under global radiation. However increasing air mass leads to
a reduction in the short circuit current of 81.73%. The efficiency
decreases with increasing atmospheric turbidity and air mass.
Abstract: Axial flow fans, while incapable of developing high
pressures, they are well suitable for handling large volumes of air at
relatively low pressures. In general, they are low in cost and possess
good efficiency, and can have blades of airfoil shape. Axial flow fans
show good efficiencies, and can operate at high static pressures if
such operation is necessary. Our objective is to model and analyze
the flow through AXIAL FANS using CFD Software and draw
inference from the obtained results, so as to get maximum efficiency.
The performance of an axial fan was simulated using CFD and the
effect of variation of different parameters such as the blade number,
noise level, velocity, temperature and pressure distribution on the
blade surface was studied. This paper aims to present a final 3D CAD
model of axial flow fan. Adapting this model to the available
components in the market, the first optimization was done. After this
step, CFX flow solver is used to do the necessary numerical analyses
on the aerodynamic performance of this model. This analysis results
in a final optimization of the proposed 3D model which is presented
in this article.
Abstract: Self-compacting concrete (SCC) developed in Japan
in the late 80s has enabled the construction industry to reduce
demand on the resources, improve the work condition and also
reduce the impact of environment by elimination of the need for
compaction. Fuzzy logic (FL) approaches has recently been used to
model some of the human activities in many areas of civil
engineering applications. Especially from these systems in the model
experimental studies, very good results have been obtained. In the
present study, a model for predicting compressive strength of SCC
containing various proportions of fly ash, as partial replacement of
cement has been developed by using Fuzzy Inference System (FIS).
For the purpose of building this model, a database of experimental
data were gathered from the literature and used for training and
testing the model. The used data as the inputs of fuzzy logic models
are arranged in a format of five parameters that cover the total binder
content, fly ash replacement percentage, water content,
superplasticizer and age of specimens. The training and testing results
in the fuzzy logic model have shown a strong potential for predicting
the compressive strength of SCC containing fly ash in the considered
range.
Abstract: Metal matrix composites (MMCs) attract considerable
attention as a result from its ability in providing a high strength, high
modulus, high toughness, high impact properties, improving wear
resistance and providing good corrosion resistance compared to
unreinforced alloy. Aluminium Silicon (Al/Si) alloy MMC has been
widely used in various industrial sectors such as in transportation,
domestic equipment, aerospace, military, construction, etc.
Aluminium silicon alloy is an MMC that had been reinforced with
aluminium nitrate (AlN) particle and become a new generation
material use in automotive and aerospace sector. The AlN is one of
the advance material that have a bright prospect in future since it has
features such as lightweight, high strength, high hardness and
stiffness quality. However, the high degree of ceramic particle
reinforcement and the irregular nature of the particles along the
matrix material that contribute to its low density is the main problem
which leads to difficulties in machining process. This paper examined
the tool wear when milling AlSi/AlN Metal Matrix Composite using
a TiB2 (Titanium diboride) coated carbide cutting tool. The volume
of the AlN reinforced particle was 10% and milling process was
carried out under dry cutting condition. The TiB2 coated carbide
insert parameters used were at the cutting speed of (230, 300 and
370m/min, feed rate of 0.8, Depth of Cut (DoC) at 0.4m). The
Sometech SV-35 video microscope system used to quantify of the
tool wear. The result shown that tool life span increasing with the
cutting speeds at (370m/min, feed rate of 0.8mm/tooth and DoC at
0.4mm) which constituted an optimum condition for longer tool life
lasted until 123.2 mins. Meanwhile, at medium cutting speed which
at 300m/m, feed rate of 0.8mm/tooth and depth of cut at 0.4mm we
found that tool life span lasted until 119.86 mins while at low cutting
speed it lasted in 119.66 mins. High cutting speed will give the best
parameter in cutting AlSi/AlN MMCs material. The result will help
manufacturers in machining process of AlSi/AlN MMCs materials.
Abstract: Red blood cells (RBC) are the most common types of
blood cells and are the most intensively studied in cell biology. The
lack of RBCs is a condition in which the amount of hemoglobin level
is lower than normal and is referred to as “anemia”. Abnormalities in
RBCs will affect the exchange of oxygen. This paper presents a
comparative study for various techniques for classifying the RBCs as
normal or abnormal (anemic) using WEKA. WEKA is an open
source consists of different machine learning algorithms for data
mining applications. The algorithms tested are Radial Basis Function
neural network, Support vector machine, and K-Nearest Neighbors
algorithm. Two sets of combined features were utilized for
classification of blood cells images. The first set, exclusively consist
of geometrical features, was used to identify whether the tested blood
cell has a spherical shape or non-spherical cells. While the second
set, consist mainly of textural features was used to recognize the
types of the spherical cells. We have provided an evaluation based on
applying these classification methods to our RBCs image dataset
which were obtained from Serdang Hospital - Malaysia, and
measuring the accuracy of test results. The best achieved
classification rates are 97%, 98%, and 79% for Support vector
machines, Radial Basis Function neural network, and K-Nearest
Neighbors algorithm respectively.
Abstract: We present an analytical model for the calculation of
the sensitivity, the spectral current noise and the detective parameter
for an optically illuminated In0.53Ga0.47As n+nn+ diode. The
photocurrent due to the excess carrier is obtained by solving the
continuity equation. Moreover, the current noise level is evaluated at
room temperature and under a constant voltage applied between the
diode terminals. The analytical calculation of the current noise in the
n+nn+ structure is developed by considering the free carries
fluctuations. The responsivity and the detection parameter are
discussed as functions of the doping concentrations and the emitter
layer thickness in one-dimensional homogeneous n+nn+ structure.
Abstract: Lead being a toxic heavy metal that mankind is
exposed to the highest levels of this metal from environmental
pollutants. A total of 180 Male scalp hair samples were collected
from different environments in Greater Cairo (GC), i.e. industrial,
heavy traffic and rural areas (60 samples from each) having different
activities during the period of, 1/5/2010 to 1/11/2012. Hair samples
were collected during five stages. Data proved that the concentration
of lead in male industrial areas of Cairo ranged between 6.2847 to
19.0432 μg/g, with mean value of 12.3288 μg/g. On the other hand,
lead content of hair samples of residential-traffic areas ranged
between 2.8634 to 16.3311 μg/g with mean value of 9.7552 μg/g.
While lead concentration on the hair of the male residents living in
rural area ranged between 1.0499-9.0402μg/g with mean value of
4.7327 μg/g. The Pb concentration in scalp hair of Cairo residents of
residential-traffic and rural traffic areas was observed to follow the
same pattern. The pattern was that of decrease concentration of
summer and its increase in winter. Then, there was a marked increase
in Pb concentration of summer 2012, and this increase was
significant. These were obviously seen for the residential-traffic and
rural areas residents. Pb pollution in residents of industrial areas
showed the same seasonal pattern, but there was marked to decrease
in Pb concentration of summer 2012, and this decrease was
significant. Lead pollution in residents of GC was serious. It is worth
noting that the atmosphere is still contaminated by lead despite a
decade of using unleaded gasoline. Strong seasonal variation in
higher Pb concentration on winter than in summer was found. Major
contributions to the pollution with Pb could include industry
emissions, motor vehicle emissions and long transported dust from
outside Cairo. More attention should be paid to the reduction of Pb
content of the urban aerosol and to the Pb pollution health.
Abstract: Several of the practical industrial control processes are
multivariable processes. Due to the relation amid the variables
(interaction), delay in the loops, it is very intricate to design a
controller directly for these processes. So first, the interaction of the
variables is analyzed using Relative Normalized Gain Array
(RNGA), which considers the time constant, static gain and delay
time of the processes. Based on the effect of RNGA, relative gain
array (RGA) and NI, the pair (control configuration) of variables to
be controlled by decentralized control is selected. The equivalent
transfer function (ETF) of the process model is estimated as first
order process with delay using the corresponding elements in the
Relative gain array and Relative average residence time array
(RARTA) of the processes. Secondly, a decentralized Proportional-
Integral (PI) controller is designed for each ETF simply using
frequency response specifications. Finally, the performance and
robustness of the algorithm is comparing with existing related
approaches to validate the effectiveness of the projected algorithm.
Abstract: Exact solution of an unsteady flow of elastico-viscous
electrically conducting fluid through a porous media in a tube of
elliptical cross section under the influence of constant pressure
gradient and magnetic field has been obtained in this paper. Initially,
the flow is generated by a constant pressure gradient. After attaining
the steady state, the pressure gradient is suddenly withdrawn and the
resulting fluid motion in a tube of elliptical cross section by taking
into account of the transverse magnetic field and porosity factor of
the bounding surface is investigated. The problem is solved in twostages
the first stage is a steady motion in tube under the influence of
a constant pressure gradient, the second stage concern with an
unsteady motion. The problem is solved employing separation of
variables technique. The results are expressed in terms of a nondimensional
porosity parameter (K), magnetic parameter (m) and
elastico-viscosity parameter (β), which depends on the Non-
Newtonian coefficient. The flow parameters are found to be identical
with that of Newtonian case as elastic-viscosity parameter and
magnetic parameter tends to zero and porosity tends to infinity. It is
seen that the effect of elastico-viscosity parameter, magnetic
parameter and the porosity parameter of the bounding surface has
significant effect on the velocity parameter.
Abstract: The edge waviness in hot rolled steel is a common
defect. Variables that affect such defect include raw material and
machine. These variables are necessary to consider to understand
such defect. This research studied the defect of edge waviness for SS
400 of metal sheet manufacture. Defect of metal sheets were divided
into two groups. The specimens were investigated on chemical
composition and mechanical properties to find the difference. The
results of investigation showed that the difference was not significant.
Therefore the roll mill machine should be used to adjust to support
another location on a roller to avoide edge waviness.
Abstract: In this paper, the dynamic characteristics of a threelobe
journal bearing lubricated with micropolar fluids are determined
by the linear stability theory. Lubricating oil containing additives and
contaminants is modelled as micropolar fluid. The modified
Reynolds equation is obtained using the micropolar lubrication theory
.The finite difference technique has been used to determine the
solution of the modified Reynolds equation. The dynamic
characteristics in terms of stiffness, damping coefficients, the critical
mass and whirl ratio are determined for various values of size of
material characteristic length and the coupling number. The
computed results show that the three-lobe bearing lubricated with
micropolar fluid exhibits better stability compared with that
lubricated with Newtonian fluid. According to the results obtained,
the effect of the parameter micropolar fluid is remarkable on the
dynamic characteristics and stability of the three-lobe bearing.
Abstract: Environmental management implementation is
presently one of the ways of organization success and value
improvement. Increasing an organization motivation to
environmental measures introduction is caused primarily by the rising
pressure of the society that generates various incentives to endeavor
for the environmental performance improvement.
The aim of the paper is to identify and characterize the key
incentives and expectations leading organizations to the
environmental management implementation. The author focuses on
five businesses of different size and field, operating in the Czech
Republic. The qualitative approach and grounded theory procedure
are used in research.
The results point out that the significant incentives for
environmental management implementation represent primarily
demands of customers, the opportunity to declare the environmental
commitment and image improvement. The researched enterprises less
commonly expect the economical contribution, competitive
advantage increase or export rate improvement. The results show that
marketing contributions are primarily expected from the
environmental management implementation.
Abstract: In this paper a comprehensive review on various
factory layouts has been carried out for designing a lucrative process
layout for medium scale industries. Industry data base reveals that the
end product rejection rate is on the order of 10% amounting large
profit loss. In order to avoid these rejection rates and to increase the
quality product production an intermediate non-destructive testing
facility (INDTF) has been recommended for increasing the overall
profit. We observed through detailed case studies that while
introducing INDTF to medium scale industries the expensive
production process can be avoided to the defective products well
before its final shape. Additionally, the defective products identified
during the intermediate stage can be effectively utilized for other
applications or recycling; thereby the overall wastage of the raw
materials can be reduced and profit can be increased. We concluded
that the prudent design of a factory layout through critical path
method facilitating with INDTF will warrant profitable outcome.
Abstract: In this paper, Fuzzy C-Means clustering with
Expectation Maximization-Gaussian Mixture Model based hybrid
modeling algorithm is proposed for Continuous Tamil Speech
Recognition. The speech sentences from various speakers are used
for training and testing phase and objective measures are between the
proposed and existing Continuous Speech Recognition algorithms.
From the simulated results, it is observed that the proposed algorithm
improves the recognition accuracy and F-measure up to 3% as
compared to that of the existing algorithms for the speech signal from
various speakers. In addition, it reduces the Word Error Rate, Error
Rate and Error up to 4% as compared to that of the existing
algorithms. In all aspects, the proposed hybrid modeling for Tamil
speech recognition provides the significant improvements for speechto-
text conversion in various applications.
Abstract: This paper reports a structured literature review of the
application of Health Information Technology in developing
countries, defined as the World Bank categories Low-income
countries, Lower-middle-income, and Upper-middle-income
countries. The aim was to identify and classify the various
applications of health information technology to assess its current
state in developing countries and explore potential areas of research.
We offer specific analysis and application of HIT in Libya as one of
the developing countries. A structured literature review was
conducted using the following online databases: IEEE, Science
Direct, PubMed, and Google Scholar. Publication dates were set for
2000-2013. For the PubMed search, publications in English, French,
and Arabic were specified. Using a content analysis approach, 159
papers were analyzed and a total number of 26 factors were identified
that affect the adoption of health information technology. Of the 2681
retrieved articles, 159 met the inclusion criteria which were carefully
analyzed and classified. The implementation of health information
technology across developing countries is varied. Whilst it was
initially expected financial constraints would have severely limited
health information technology implementation, some developing
countries like India have nevertheless dominated the literature and
taken the lead in conducting scientific research. Comparing the
number of studies to the number of countries in each category, we
found that Low-income countries and Lower-middle-income had
more studies carried out than Upper-middle-income countries.
However, whilst IT has been used in various sectors of the economy,
the healthcare sector in developing countries is still failing to benefit
fully from the potential advantages that IT can offer.
Abstract: The objective of meta-analysis is to combine results
from several independent studies in order to create generalization
and provide evidence base for decision making. But recent studies
show that the magnitude of effect size estimates reported in many
areas of research significantly changed over time and this can
impair the results and conclusions of meta-analysis. A number of
sequential methods have been proposed for monitoring the effect
size estimates in meta-analysis. However they are based on statistical
theory applicable only to fixed effect model (FEM) of meta-analysis.
For random-effects model (REM), the analysis incorporates the
heterogeneity variance, τ 2 and its estimation create complications.
In this paper we study the use of a truncated CUSUM-type test with
asymptotically valid critical values for sequential monitoring in REM.
Simulation results show that the test does not control the Type I error
well, and is not recommended. Further work required to derive an
appropriate test in this important area of applications.
Abstract: This paper aims to represent the commercial activity
of a city taking as source data the social network Foursquare. The
city of Murcia is selected as case study, and the location-based
social network Foursquare is the main source of information. After
carrying out a reorganisation of the user-generated data extracted
from Foursquare, it is possible to graphically display on a map the
various city spaces and venues especially those related to commercial,
food and entertainment sector businesses. The obtained visualisation
provides information about activity patterns in the city of Murcia
according to the people‘s interests and preferences and, moreover,
interesting facts about certain characteristics of the town itself.