Abstract: Laplace transformations have wide applications in
engineering and sciences. All previous studies of modified Laplace
transformations depend on differential equation with initial
conditions. The purpose of our paper is to solve the linear differential
equations (not initial value problem) and then find the general
solution (not particular) via the Laplace transformations without
needed any initial condition. The study involves both types of
differential equations, ordinary and partial.
Abstract: The final step to complete the “Analytical Systems
Engineering Process” is the “Allocated Architecture” in which all
Functional Requirements (FRs) of an engineering system must be
allocated into their corresponding Physical Components (PCs). At
this step, any design for developing the system’s allocated
architecture in which no clear pattern of assigning the exclusive
“responsibility” of each PC for fulfilling the allocated FR(s) can be
found is considered a poor design that may cause difficulties in
determining the specific PC(s) which has (have) failed to satisfy a
given FR successfully. The present study utilizes the Axiomatic
Design method principles to mathematically address this problem and
establishes an “Axiomatic Model” as a solution for reaching good
alternatives for developing the allocated architecture. This study
proposes a “loss Function”, as a quantitative criterion to monetarily
compare non-ideal designs for developing the allocated architecture
and choose the one which imposes relatively lower cost to the
system’s stakeholders. For the case-study, we use the existing design
of U. S. electricity marketing subsystem, based on data provided by
the U.S. Energy Information Administration (EIA). The result for
2012 shows the symptoms of a poor design and ineffectiveness due to
coupling among the FRs of this subsystem.
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: Machining parameters are very important in
determining the surface quality of any material. In the past decade,
some new engineering materials were developed for the
manufacturing industry which created a need to conduct an
investigation on the impact of the said parameters on their surface
roughness. Polyurethane (PU) block is widely used in the automotive
industry to manufacture parts such as checking fixtures that are used
to verify the dimensional accuracy of automotive parts. In this paper,
the design of experiment (DOE) was used to investigate on the effect
of the milling parameters on the PU block. Furthermore, an analysis
of the machined surface chemical composition was done using
scanning electron microscope (SEM). It was found that the surface
roughness of the PU block is severely affected when PU undergoes a
flood machining process instead of a dry condition. In addition the
stepover and the silicon content were found to be the most significant
parameters that influence the surface quality of the PU block.
Abstract: Safety is one of the most important considerations
when buying a new car. While active safety aims at avoiding
accidents, passive safety systems such as airbags and seat belts
protect the occupant in case of an accident. In addition to legal
regulations, organizations like Euro NCAP provide consumers with
an independent assessment of the safety performance of cars and
drive the development of safety systems in automobile industry.
Those ratings are mainly based on injury assessment reference values
derived from physical parameters measured in dummies during a car
crash test.
The components and sub-systems of a safety system are designed
to achieve the required restraint performance. Sled tests and other
types of tests are then carried out by car makers and their suppliers
to confirm the protection level of the safety system. A Knowledge
Discovery in Databases (KDD) process is proposed in order to
minimize the number of tests. The KDD process is based on the
data emerging from sled tests according to Euro NCAP specifications.
About 30 parameters of the passive safety systems from different data
sources (crash data, dummy protocol) are first analysed together with
experts opinions. A procedure is proposed to manage missing data
and validated on real data sets. Finally, a procedure is developed to
estimate a set of rough initial parameters of the passive system before
testing aiming at reducing the number of tests.
Abstract: Bamboo is extensively used in construction industry.
Low durability of bamboo due to fungus infestation and termites
attack under storage puts certain constrains for it usage as modern
structural material. Looking at many chemical formulations for
bamboo treatment leading to severe harmful environment effects,
research on eco-friendly preservatives for bamboo treatment has been
initiated world-over. In the present studies, eco-friendly preservative
for bamboo treatment has been developed. To validate its application
for structural purposes, investigation of effect of treatment on
compressive strength has been investigated. Neemoil (25%)
integrated with copper naphthenate (0.3%) on dilution with kerosene
oil impregnated into bamboo culm at 2 bar pressure, has shown
weight loss of only 3.15% in soil block analysis method. The results
from compressive strength analysis using HEICO Automatic
Compression Testing Machine reveal that preservative treatment has
not altered the structural properties of bamboo culms. Compressive
strength of control (11.72 N/mm2) and above treated samples (11.71
N/mm2) was found to be comparable.
Abstract: Electricity spot prices are highly volatile under
optimal generation capacity scenarios due to factors such as nonstorability
of electricity, peak demand at certain periods, generator
outages, fuel uncertainty for renewable energy generators, huge
investments and time needed for generation capacity expansion etc.
As a result market participants are exposed to price and volume risk,
which has led to the development of risk management practices. This
paper provides an overview of risk management practices by market
participants in electricity markets using financial derivatives.
Abstract: Fuzzy inference method based approach to the
forming of modular intellectual system of assessment the quality of
communication services is proposed. Developed under this approach
the basic fuzzy estimation model takes into account the
recommendations of the International Telecommunication Union in
respect of the operation of packet switching networks based on IPprotocol.
To implement the main features and functions of the fuzzy
control system of quality telecommunication services it is used
multilayer feedforward neural network.
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: In this work, we propose and analyze a model of
Phytoplankton-Zooplankton interaction with harvesting considering
that some species are exploited commercially for food. Criteria for
local stability, instability and global stability are derived and some
threshold harvesting levels are explored to maintain the population
at an appropriate equilibrium level even if the species are exploited
continuously.Further,biological and bionomic equilibria of the system
are obtained and an optimal harvesting policy is also analysed using
the Pantryagin’s Maximum Principle.Finally analytical findings are
also supported by some numerical simulations.
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: The levels of maximum power density of GSM
signals in the cities of Lagos, Ibadan and Abuja were studied.
Measurements were made with a calibrated hand held spectrum
analyzer 200m away from 271 base stations, at 1.2m to the ground
level. The maximum GSM 900 signal power density was
139.63μW/m2 in Lagos, 162.49μW/m2 in Ibadan and 5411.26μW/m2
in Abuja. Also, the maximum GSM 1800 signal power density was
296.82μW/m2 in Lagos, 116.82μW/m2 in Ibadan and 1263.00μW/m2
in Abuja. The level of power density of GSM 900 and GSM 1800
signals in the cities of Lagos, Ibadan and Abuja are far less than the
recommended value of 4.5W/m2 for GSM 900 and 9.0 W/m2 for
GSM 1800 by the ICNRP guideline. It can be concluded that
exposure to GSM signals in these cities cannot contribute to the
health detriments caused by thermal effects of radiofrequency
radiation.
Abstract: Image spam is a kind of email spam where the spam
text is embedded with an image. It is a new spamming technique
being used by spammers to send their messages to bulk of internet
users. Spam email has become a big problem in the lives of internet
users, causing time consumption and economic losses. The main
objective of this paper is to detect the image spam by using histogram
properties of an image. Though there are many techniques to
automatically detect and avoid this problem, spammers employing
new tricks to bypass those techniques, as a result those techniques are
inefficient to detect the spam mails. In this paper we have proposed a
new method to detect the image spam. Here the image features are
extracted by using RGB histogram, HSV histogram and combination
of both RGB and HSV histogram. Based on the optimized image
feature set classification is done by using k- Nearest Neighbor(k-NN)
algorithm. Experimental result shows that our method has achieved
better accuracy. From the result it is known that combination of RGB
and HSV histogram with k-NN algorithm gives the best accuracy in
spam detection.
Abstract: Now-a-days autonomous mobile robots have found
applications in diverse fields. An autonomous robot system must be
able to behave in an intelligent manner to deal with complex and
changing environment. This work proposes the performance of path
planning and navigation of autonomous mobile robot using
Gravitational Search Algorithm (GSA), Simulated Annealing (SA)
and Particle Swarm optimization (PSO) based intelligent controllers
in an unstructured environment. The approach not only finds a valid
collision free path but also optimal one. The main aim of the work is
to minimize the length of the path and duration of travel from a
starting point to a target while moving in an unknown environment
with obstacles without collision. Finally, a comparison is made
between the three controllers, it is found that the path length and time
duration made by the robot using GSA is better than SA and PSO
based controllers for the same work.
Abstract: Steganography is the art and science that hides the information in an appropriate cover carrier like image, text, audio and video media. In this work the authors propose a new image based steganographic method for hiding information within the complex bit planes of the image. After slicing into bit planes the cover image is analyzed to extract the most complex planes in decreasing order based on their bit plane complexity. The complexity function next determines the complex noisy blocks of the chosen bit plane and finally pixel mapping method (PMM) has been used to embed secret bits into those regions of the bit plane. The novel approach of using pixel mapping method (PMM) in bit plane domain adaptively embeds data on most complex regions of image, provides high embedding capacity, better imperceptibility and resistance to steganalysis attack.
Abstract: The demand of high quality services has fueled
dimensional research and development in wireless communications
and networking. As a result, different wireless technologies like
Wireless LAN, CDMA, GSM, UMTS, MANET, Bluetooth and
satellite networks etc. have emerged in the last two decades. Future
networks capable of carrying multimedia traffic need IP convergence,
portability, seamless roaming and scalability among the existing
networking technologies without changing the core part of the
existing communications networks. To fulfill these goals, the present
networking systems are required to work in cooperation to ensure
technological independence, seamless roaming, high security and
authentication, guaranteed Quality of Services (QoS). In this paper, a
conceptual framework for a cooperative network (CN) is proposed
for integration of heterogeneous existing networks to meet out the
requirements of the next generation wireless networks.
Abstract: The growth in the volume of text data such as books
and articles in libraries for centuries has imposed to establish
effective mechanisms to locate them. Early techniques such as
abstraction, indexing and the use of classification categories have
marked the birth of a new field of research called "Information
Retrieval". Information Retrieval (IR) can be defined as the task of
defining models and systems whose purpose is to facilitate access to
a set of documents in electronic form (corpus) to allow a user to find
the relevant ones for him, that is to say, the contents which matches
with the information needs of the user.
Most of the models of information retrieval use a specific data
structure to index a corpus which is called "inverted file" or "reverse
index".
This inverted file collects information on all terms over the corpus
documents specifying the identifiers of documents that contain the
term in question, the frequency of each term in the documents of the
corpus, the positions of the occurrences of the word...
In this paper we use an oriented object database (db4o) instead of
the inverted file, that is to say, instead to search a term in the inverted
file, we will search it in the db4o database.
The purpose of this work is to make a comparative study to see if
the oriented object databases may be competing for the inverse index
in terms of access speed and resource consumption using a large
volume of data.
Abstract: Heavy rare earth (HRE) oxalate concentrates were
prepared from the Egyptian crude monazite sand (graded about 47%).
The concentrates were specified quantitatively for their constituents
of individual rare earth elements using ion chromatograph (IC) and
qualitatively by scanning electron microscope (SEM) for the other
major constituents. The 1st concentrate was composed of 10.5%
HREE where 7.25% of them represented yttrium. The 2nd concentrate
contained about 41.7% LREE, 17.5% HREE and 13.6% Th. The
LREE involved 18.3% Ce, 10.5% La and 8% Nd while the HREE
were 8.7% Y, 3.5% Gd and 2.9% Dy. The 3rd concentrate was
containing about 8.0% LREE (3.7% Ce, 2.0% La and 1.5% Nd),
10.2% HREE (6.4% yttrium and 2.0% Dy) and 2.1% uranium. The
final concentrate comprised 0.84% uranium beside iron, chromium
and traces of REE.
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: The study is devoted to define the optimal conditions
for the nitriding of pure iron at atmospheric pressure by using NH3-
Ar-C3H8 gas mixtures. After studying the mechanisms of phase
formation and mass transfer at the gas-solid interface, a mathematical
model is developed in order to predict the nitrogen transfer rate in the
solid, the ε-carbonitride layer growth rate and the nitrogen and
carbon concentration profiles. In order to validate the model and to
show its possibilities, it is compared with thermogravimetric
experiments, analyses and metallurgical observations (X-ray
diffraction, optical microscopy and electron microprobe analysis).
Results obtained allow us to demonstrate the sound correlation
between the experimental results and the theoretical predictions.