Abstract: Wavelength Division Multiplexing (WDM)
technology is the most promising technology for the proper
utilization of huge raw bandwidth provided by an optical fiber. One
of the key problems in implementing the all-optical WDM network is
the packet contention. This problem can be solved by several
different techniques. In time domain approach the packet contention
can be reduced by incorporating Fiber Delay Lines (FDLs) as optical
buffer in the switch architecture. Different types of buffering
architectures are reported in literatures. In the present paper a
comparative performance analysis of three most popular FDL
architectures are presented in order to obtain the best contention
resolution performance. The analysis is further extended to consider
the effect of different fiber non-linearities on the network
performance.
Abstract: In this paper, we introduce a flexible box erecting
machine (BEM) that swiftly and automatically transforms cardboard
into a three dimensional box. Recently, the parcel service and
home-shopping industries have grown rapidly, and there is an
increasing need for various box types to ship various products.
However, workers cannot fold thousands of boxes manually in a day.
As such, automatic BEMs are garnering greater attention. This study
takes equipment operation into consideration as well as mechanical
improvements in order to design a BEM that is able to outperform its
conventional counterparts. We analyzed six dispatching rules – First In
First Out (FIFO), Shortest Processing Time (SPT), Earliest Due Date
(EDD), Setup Avoidance, EDD + SPT, and EDD + Setup Avoidance –
to determine which one was most suitable for BEM operation.
Consequently, SPT and Setup Avoidance were found to be the most
critical rules, followed by EDD + Setup Avoidance, EDD + SPT,
EDD, and FIFO. This hierarchy was valid for both our conventional
BEM and our new flexible BEM from the viewpoint of processing
time. We believe that this research can contribute to flexible BEM
management, which has the potential to increase productivity and
convenience.
Abstract: Fresh concrete has one of dynamic properties known
as slump. Slump of concrete is design to compatible with placing
method. Due to hydration reaction of cement, the slump of concrete
is loss through time. Therefore, delayed concrete probably get reject
because slump is unacceptable. In order to recover the slump of
delayed concrete the second dose of superplasticizer (naphthalene
based type F) is added into the system, the slump recovery can be
done as long as the concrete is not setting. By adding superplasticizer
as solution for recover unusable slump loss concrete may affects
other concrete properties. Therefore, this paper was observed setting
times and compressive strength of concrete after being re-dose with
chemical admixture type F (superplasticizer, naphthalene based) for
slump recovery. The concrete used in this study was fly ash concrete
with fly ash replacement of 0%, 30% and 50% respectively. Concrete
mix designed for test specimen was prepared with paste content (ratio
of volume of cement to volume of void in the aggregate) of 1.2 and
1.3, water-to-binder ratio (w/b) range of 0.3 to 0.58, initial dose of
superplasticizer (SP) range from 0.5 to 1.6%. The setting times of
concrete were tested both before and after re-dosed with different
amount of second dose and time of dosing. The research was
concluded that addition of second dose of superplasticizer would
increase both initial and final setting times accordingly to dosage of
addition. As for fly ash concrete, the prolongation effect was higher
as the replacement of fly ash increase. The prolongation effect can
reach up to maximum about 4 hours. In case of compressive strength,
the re-dosed concrete has strength fluctuation within acceptable range
of ±10%.
Abstract: The research investigates the causes of unemployment
in Namibia, Nigeria and South Africa and the role of Capital
Accumulation in reducing the unemployment profile of these
economies as proposed by the post-Keynesian economics. This is
conducted through extensive review of literature on the NAIRU
models and focused on the post-Keynesian view of unemployment
within the NAIRU framework. The NAIRU (non-accelerating
inflation rate of unemployment) model has become a dominant
framework used in macroeconomic analysis of unemployment. The
study views the post-Keynesian economics arguments that capital
accumulation is a major determinant of unemployment.
Unemployment remains the fundamental socio-economic challenge
facing African economies. It has been a burden to citizens of those
economies. Namibia, Nigeria, and South Africa are great African
nations battling with high unemployment rates. The high
unemployment rate in the country led the citizens to chase away
foreigners in the country claiming that they have taken away their
jobs. The study proposes there is a strong relationship between
capital accumulation and unemployment in Namibia, Nigeria, and
South Africa, and capital accumulation is responsible for high
unemployment rates in these countries. For the economies to achieve
steady state level of employment and satisfactory level of economic
growth and development, there is need for capital accumulation to
take place. The countries in the study have been selected after a
critical research and investigations. They are selected based on the
following criteria; African economies with high unemployment rates
above 15% and have about 40% of their workforce unemployed. This
level of unemployment is the critical level of unemployment in
Africa as expressed by International Labour Organization (ILO). And
finally, the African countries experience a slow growth in their Gross
fixed capital formation. Adequate statistical measures have been
employed using a time-series analysis in the study and the results
revealed that capital accumulation is the main driver of
unemployment performance in the chosen African countries. An
increase in the accumulation of capital causes unemployment to
reduce significantly. The results of the research work will be useful
and relevant to federal governments and ministries, departments and
agencies (MDAs) of Namibia, Nigeria and South Africa to resolve
the issue of high and persistent unemployment rates in their
economies which are great burden that slows growth and
development of developing economies. Also, the result can be useful
to World Bank, African Development Bank and International Labour
Organization (ILO) in their further research and studies on how to
tackle unemployment in developing and emerging economies.
Abstract: Average temperatures worldwide are expected to
continue to rise. At the same time, major cities in developing
countries are becoming increasingly populated and polluted.
Governments are tasked with the problem of overheating and air
quality in residential buildings. This paper presents the development
of a model, which is able to estimate the occupant exposure
to extreme temperatures and high air pollution within domestic
buildings. Building physics simulations were performed using the
EnergyPlus building physics software. An accurate metamodel is
then formed by randomly sampling building input parameters and
training on the outputs of EnergyPlus simulations. Metamodels are
used to vastly reduce the amount of computation time required when
performing optimisation and sensitivity analyses. Neural Networks
(NNs) have been compared to a Radial Basis Function (RBF)
algorithm when forming a metamodel. These techniques were
implemented using the PyBrain and scikit-learn python libraries,
respectively. NNs are shown to perform around 15% better than RBFs
when estimating overheating and air pollution metrics modelled by
EnergyPlus.
Abstract: The increase in electric power demand in face of
environmental issues has intensified the participation of renewable
energy sources such as photovoltaics, in the energy matrix of various
countries. Due to their operational characteristics, they can generate
time-varying harmonic and inter-harmonic distortions. For this
reason, the application of methods of measurement based on
traditional Fourier analysis, as proposed by IEC 61000-4-7, can
provide inaccurate results. Considering the aspects mentioned herein,
came the idea of the development of this work which aims to present
the results of a comparative evaluation between a methodology
arising from the combination of the Prony method with the Kalman
filter and another method based on the IEC 61000-4-30 and IEC
61000-4-7 standards. Employed in this study were synthetic signals
and data acquired through measurements in a 50kWp photovoltaic
installation.
Abstract: Social networking sites such as Twitter and Facebook
attracts over 500 million users across the world, for those users, their
social life, even their practical life, has become interrelated. Their
interaction with social networking has affected their life forever.
Accordingly, social networking sites have become among the main
channels that are responsible for vast dissemination of different kinds
of information during real time events. This popularity in Social
networking has led to different problems including the possibility of
exposing incorrect information to their users through fake accounts
which results to the spread of malicious content during life events.
This situation can result to a huge damage in the real world to the
society in general including citizens, business entities, and others. In this paper, we present a classification method for detecting the
fake accounts on Twitter. The study determines the minimized set of
the main factors that influence the detection of the fake accounts on
Twitter, and then the determined factors are applied using different
classification techniques. A comparison of the results of these
techniques has been performed and the most accurate algorithm is
selected according to the accuracy of the results. The study has been
compared with different recent researches in the same area; this
comparison has proved the accuracy of the proposed study. We claim
that this study can be continuously applied on Twitter social network
to automatically detect the fake accounts; moreover, the study can be
applied on different social network sites such as Facebook with minor
changes according to the nature of the social network which are
discussed in this paper.
Abstract: This paper deals with using of prevailing operation
system MS Office (SmartArt...) for mathematical models, using
DYVELOP (Dynamic Vector Logistics of Processes) method. It
serves for crisis situations investigation and modelling within the
organizations of critical infrastructure. In first part of paper, it will be
introduced entities, operators, and actors of DYVELOP method. It
uses just three operators of Boolean algebra and four types of the
entities: the Environments, the Process Systems, the Cases, and the
Controlling. The Process Systems (PrS) have five “brothers”:
Management PrS, Transformation PrS, Logistic PrS, Event PrS and
Operation PrS. The Cases have three “sisters”: Process Cell Case,
Use Case, and Activity Case. They all need for the controlling of
their functions special Ctrl actors, except ENV – it can do without
Ctrl. Model´s maps are named the Blazons and they are able
mathematically - graphically express the relationships among entities,
actors and processes. In second part of this paper, the rich blazons of
DYVELOP method will be used for the discovering and modelling of
the cycling cases and their phases. The blazons need live PowerPoint
presentation for better comprehension of this paper mission. The
crisis management of energetic crisis infrastructure organization is
obliged to use the cycles for successful coping of crisis situations.
Several times cycling of these cases is necessary condition for the
encompassment for both emergency events and the mitigation of
organization´s damages. Uninterrupted and continuous cycling
process brings for crisis management fruitfulness and it is good
indicator and controlling actor of organizational continuity and its
sustainable development advanced possibilities. The research reliable
rules are derived for the safety and reliable continuity of energetic
critical infrastructure organization in the crisis situation.
Abstract: Prior literature in the field of adaptive and
personalized learning sequence in e-learning have proposed and
implemented various mechanisms to improve the learning process
such as individualization and personalization, but complex to
implement due to expensive algorithmic programming and need of
extensive and prior data. The main objective of personalizing
learning sequence is to maximize learning by dynamically selecting
the closest teaching operation in order to achieve the learning
competency of learner. In this paper, a revolutionary technique has
been proposed and tested to perform individualization and
personalization using modified reversed roulette wheel selection
algorithm that runs at O(n). The technique is simpler to implement
and is algorithmically less expensive compared to other revolutionary
algorithms since it collects the dynamic real time performance matrix
such as examinations, reviews, and study to form the RWSA single
numerical fitness value. Results show that the implemented system is
capable of recommending new learning sequences that lessens time
of study based on student's prior knowledge and real performance
matrix.
Abstract: In this paper, de Laval rotor system has been
characterized by a hinge model and its transient response numerically
treated for a dynamic solution. The effect of the ensuing non-linear
disturbances namely rub and breathing crack is numerically
simulated. Subsequently, three analysis methods: Orbit Analysis, Fast
Fourier Transform (FFT), and Wavelet Transform (WT) are
employed to extract features of the vibration signal of the faulty
system. An analysis of the system response orbits clearly indicates
the perturbations due to the rotor-to-stator contact. The sensitivities
of WT to the variation in system speed have been investigated by
Continuous Wavelet Transform (CWT). The analysis reveals that
features of crack, rubs and unbalance in vibration response can be
useful for condition monitoring. WT reveals its ability to detect nonlinear
signal, and obtained results provide a useful tool method for
detecting machinery faults.
Abstract: This paper presents the development of a mobile
application for students at the Faculty of Information Technology,
Rangsit University (RSU), Thailand. RSU upgrades an enrollment
process by improving its information systems. Students can
download the RSU APP easily in order to access the RSU substantial
information. The reason of having a mobile application is to help
students to access the system regardless of time and place. The objectives of this paper include: 1. To develop an application
on iOS platform for those students at the Faculty of Information
Technology, Rangsit University, Thailand. 2. To obtain the students’
perception towards the new mobile app. The target group is those
from the freshman year till the senior year of the faculty of
Information Technology, Rangsit University. The new mobile application, called as RSU APP, is developed by
the department of Information Technology, Rangsit University. It
contains useful features and various functionalities particularly on
those that can give support to students. The core contents of the app
consist of RSU’s announcement, calendar, events, activities, and ebook.
The mobile app is developed on the iOS platform. The user
satisfaction is analyzed from the interview data from 81 interviewees
as well as a Google application like a Google form which 122
interviewees are involved. The result shows that users are satisfied
with the application as they score it the most satisfaction level at 4.67
SD 0.52. The score for the question if users can learn and use the
application quickly is high which is 4.82 SD 0.71. On the other hand,
the lowest satisfaction rating is in the app’s form, apps lists, with the
satisfaction level as 4.01 SD 0.45.
Abstract: Hydrogen produced by means of polymer electrolyte
membrane electrolyzer (PEME) is one of the most promising
methods due to clean and renewable energy source. In the process,
some energy loss due to mass transfer through a PEM is caused by
diffusion, electro-osmotic drag, and the pressure difference between
the cathode channel and anode channel. In PEME, water molecules
and ionic particles transferred between the electrodes from anode to
cathode, Extensive mixing of the hydrogen and oxygen at anode
channel due to gases cross-over must be avoided. In recent times the
consciousness of safety issue in high pressure PEME where the
oxygen mix with hydrogen at anode channel could create, explosive
conditions have generated a lot of concern. In this paper, the steady
state and simulation analysis of gases crossover in PEME on the
temperature and pressure effect are presented. The simulations have
been analysis in MATLAB based on the well-known Fick’s Law of
molecular diffusion. The simulation results indicated that as
temperature increases, there is a significant decrease in operating
voltage.
Abstract: In order to utilize results from global climate models,
dynamical and statistical downscaling techniques have been
developed. For dynamical downscaling, usually a limited area
numerical model is used, with associated high computational cost.
This research proposes dynamic equation for specific space-time
regional climate downscaling from the Educational Global Climate
Model (EdGCM) for Southeast Asia. The equation is for surface air
temperature. This equation provides downscaling values of surface
air temperature at any specific location and time without running a
regional climate model. In the proposed equations, surface air
temperature is approximated from ground temperature, sensible heat
flux and 2m wind speed. Results from the application of the equation
show that the errors from the proposed equations are less than the
errors for direct interpolation from EdGCM.
Abstract: Rivers have transient storage or dead zones where
injected pollutants or solutes are entrapped for considerable period of
time, known as residence time, before being released into the main
flowing zones of rivers. In this study, a new empirical expression for
residence time, implementing genetic programming on published
dispersion data, has been derived. The proposed expression uses few
hydraulic and geometric characteristics of rivers which are normally
known to the authorities. When compared with some reported
expressions, based on various statistical indices, it can be concluded
that the proposed expression predicts the residence time of pollutants
in natural rivers more accurately.
Abstract: The change of conditions for production companies in
high-wage countries is characterized by the globalization of
competition and the transition of a supplier´s to a buyer´s market. The
companies need to face the challenges of reacting flexibly to these
changes. Due to the significant and increasing degree of automation,
assembly has become the most expensive production process.
Regarding the reduction of production cost, assembly consequently
offers a considerable rationalizing potential. Therefore, an
aerodynamic feeding system has been developed at the Institute of
Production Systems and Logistics (IFA), Leibniz Universitaet
Hannover. This system has been enabled to adjust itself by using a
genetic algorithm. The longer this genetic algorithm is executed the
better is the feeding quality. In this paper, the relation between the
system´s setting time and the feeding quality is observed and a
function which enables the user to achieve the minimum of the total
feeding time is presented.
Abstract: Escherichia coli (E. coli) is the most isolated bacteria
from blood circulation of septicemic calves. Given the prevalence of
septicemia in animals and its economic importance in veterinary
practice, better understanding of changes in clinical signs following
disease, may contribute to early detection of disorder. The present
study has been carried out to detect changes of clinical signs in
induced sepsis in calves with E. coli. Colisepticemia has been
induced in 10 twenty-day old healthy Holstein- Frisian calves with
intravenous injection of 1.5 X 109 colony forming units (cfu) of
O111:H8 strain of E. coli. Clinical signs including rectal temperature,
heart rate, respiratory rate, shock, appetite, sucking reflex, feces
consistency, general behavior, dehydration and standing ability were
recorded in experimental calves during 24 hours after induction of
colisepticemia. Blood culture was also carried out from calves four
times during experiment. ANOVA with repeated measure is used to
see changes of calves’ clinical signs to experimental colisepticemia,
and values of P≤ 0.05 was considered statistically significant. Mean
values of rectal temperature and heart rate as well as median values
of respiratory rate, appetite, suckling reflex, standing ability and feces
consistency of experimental calves increased significantly during
study (P 0.05). The
results of present study showed that total score of clinical signs in
calves with experimental colisepticemia increased significantly,
although score of some clinical signs such as shock did not change
significantly.
Abstract: In this study, the effects and interactions of reaction
time and capping agent assistance during sol-gel synthesis of
magnesium substituted hydroxyapatite nanopowder (MgHA) on
hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P
ratio and mean crystallite size was examined experimentally as well
as through statistical analysis. MgHA nanopowders were synthesized
by sol-gel technique at room temperature using aqueous solution of
calcium nitrate tetrahydrate, magnesium nitrate hexahydrate and
potassium dihydrogen phosphate as starting materials. The reaction
time for sol-gel synthesis was varied between 15 to 60 minutes. Two
process routes were followed with and without addition of
triethanolamine (TEA) in the solutions. The elemental compositions
of as-synthesized powders were determined using X-ray fluorescence
(XRF) spectroscopy. The functional groups present in the assynthesized
MgHA nanopowders were established through Fourier
Transform Infrared Spectroscopy (FTIR). The amounts of phases
present, Ca/P ratio and mean crystallite sizes of MgHA nanopowders
were determined using X-ray diffraction (XRD). The HA content in
biphasic mixture of HA and β-TCP and Ca/P ratio in as-synthesized
MgHA nanopowders increased effectively with reaction time of sols
(p0.15, two way ANOVA). The MgHA nanopowders
synthesized with TEA assistance exhibited 14 nm lower crystallite
size (p
Abstract: Response Surface Methods (RSM) provide
statistically validated predictive models that can then be manipulated
for finding optimal process configurations. Variation transmitted to
responses from poorly controlled process factors can be accounted
for by the mathematical technique of propagation of error (POE),
which facilitates ‘finding the flats’ on the surfaces generated by
RSM. The dual response approach to RSM captures the standard
deviation of the output as well as the average. It accounts for
unknown sources of variation. Dual response plus propagation of
error (POE) provides a more useful model of overall response
variation. In our case, we implemented this technique in predicting
compressive strength of concrete of 28 days in age. Since 28 days is
quite time consuming, while it is important to ensure the quality
control process. This paper investigates the potential of using design
of experiments (DOE-RSM) to predict the compressive strength of
concrete at 28th day. Data used for this study was carried out from
experiment schemes at university of Benghazi, civil engineering
department. A total of 114 sets of data were implemented. ACI mix
design method was utilized for the mix design. No admixtures were
used, only the main concrete mix constituents such as cement, coarseaggregate,
fine aggregate and water were utilized in all mixes.
Different mix proportions of the ingredients and different water
cement ratio were used. The proposed mathematical models are
capable of predicting the required concrete compressive strength of
concrete from early ages.
Abstract: This study evaluated the acute toxicity and tissue
distribution of intravenously administered gold nanoparticles
(AuNPs) in male rabbits. Rabbits were exposed to single dose of
AuNPs (300 μg/ kg). Toxic effects were assessed via general
behavior, hematological parameters, serum biochemical parameters,
and histopathological examination of various rabbits’ organs.
Inductively coupled plasma–mass spectrometry (ICP-MS) was used
to determine gold concentrations in tissue samples collected at
predetermined time intervals. After one week, AuNPs exerted no
obvious acute toxicity in rabbits. However, inflammatory reactions
were observed in liver, lungs and kidneys accompanied with mild
absolute neutrophilia and significant monocytosis. The highest gold
levels were found in the spleen and liver followed by lungs, and
kidneys. These results indicated that AuNPs could be distributed
extensively to various tissues in the body, but primarily in the spleen
and liver.
Abstract: Laura Island, which is located about 50 km away from
downtown, is a source of water supply in Majuro atoll, which is the
capital of the Republic of the Marshall Islands. Low and flat Majuro
atoll has neither river nor lake. It is very important for Majuro atoll to
ensure the conservation of its water resources. However, upconing,
which is the process of partial rising of the freshwater-saltwater
boundary near the water-supply well, was caused by the excess
pumping from it during the severe drought in 1998. Upconing will
make the water usage of the freshwater lens difficult. Thus,
appropriate water usage is required to prevent up coning in the
freshwater lens because there is no other water source during drought. Numerical simulation of water usage applying SEAWAT model
was conducted at the central part of Laura Island, including the water
supply well, which was affected by upconing. The freshwater lens was
created as a result of infiltration of consistent average rainfall. The lens
shape was almost the same as the one in 1985. 0 of monthly rainfall
and variable daily pump discharge were used to calculate the
sustainable pump discharge from the water supply well. Consequently,
the total amount of pump discharge was increased as the daily pump
discharge was increased, indicating that it needs more time to recover
from upconing. Thus, a pump standard to reduce the pump intensity is
being proposed, which is based on numerical simulation concerning
the occurrence of the up-coning phenomenon in Laura Island during
the drought.