Abstract: The Euler-s equation of motion is extended to include
the viscosity stress tensor leading to the formulation of Navier–
Stokes type equation. The latter is linearized and applied to
investigate the rotational motion or vorticity in a viscous fluid.
Relations for the velocity of viscous waves and attenuation parameter
are obtained in terms of viscosity (μ) and the density (¤ü) of the fluid.
μ and ¤ü are measured experimentally as a function of temperature for
two different samples of light and heavy crude oil. These data
facilitated to determine the activation energy, velocity of viscous
wave and the attenuation parameter. Shear wave velocity in heavy oil
is found to be much larger than the light oil, whereas the attenuation
parameter in heavy oil is quite low in comparison to light one. The
activation energy of heavy oil is three times larger than light oil.
Abstract: This paper describes the development of a 16-ports optical code division multiple access (OCDMA) encoder prototype based on Arrayed Waveguide Grating (AWG) and optical switches. It is potentially to provide a high security for data transmission due to all data will be transmitted in binary code form. The output signals from AWG are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmitted to the receiver. The 16-ports encoder used 16 double pole double throw (DPDT) toggle switches to control the polarization of voltage source from +5 V to -5 V for 16 optical switches. When +5 V is given, the optical switch will give code '1' and vice versa. The experimental results showed the insertion loss, crosstalk, uniformity, and optical signal-noise-ratio (OSNR) for the developed prototype are
Abstract: A gene network gives the knowledge of the regulatory
relationships among the genes. Each gene has its activators and
inhibitors that regulate its expression positively and negatively
respectively. Genes themselves are believed to act as activators and
inhibitors of other genes. They can even activate one set of genes and
inhibit another set. Identifying gene networks is one of the most
crucial and challenging problems in Bioinformatics. Most work done
so far either assumes that there is no time delay in gene regulation or
there is a constant time delay. We here propose a Dynamic Time-
Lagged Correlation Based Method (DTCBM) to learn the gene
networks, which uses time-lagged correlation to find the potential
gene interactions, and then uses a post-processing stage to remove
false gene interactions to common parents, and finally uses dynamic
correlation thresholds for each gene to construct the gene network.
DTCBM finds correlation between gene expression signals shifted in
time, and therefore takes into consideration the multi time delay
relationships among the genes. The implementation of our method is
done in MATLAB and experimental results on Saccharomyces
cerevisiae gene expression data and comparison with other methods
indicate that it has a better performance.
Abstract: Inconel 718, a nickel based super-alloy is an
extensively used alloy, accounting for about 50% by weight of
materials used in an aerospace engine, mainly in the gas turbine
compartment. This is owing to their outstanding strength and
oxidation resistance at elevated temperatures in excess of 5500 C.
Machining is a requisite operation in the aircraft industries for the
manufacture of the components especially for gas turbines. This
paper is concerned with optimization of the surface roughness when
turning Inconel 718 with cermet inserts. Optimization of turning
operation is very useful to reduce cost and time for machining. The
approach is based on Response Surface Method (RSM). In this work,
second-order quadratic models are developed for surface roughness,
considering the cutting speed, feed rate and depth of cut as the cutting
parameters, using central composite design. The developed models
are used to determine the optimum machining parameters. These
optimized machining parameters are validated experimentally, and it
is observed that the response values are in reasonable agreement with
the predicted values.
Abstract: The effect of artificial pozzolan (waste brick) on the
physico-chemical properties of cement manufactured was
investigated. The waste brick is generated by the manufacture of
bricks. It was used in the proportions of 0%, 5%, 10%, 15% and 20%
by mass of cement to study its effect on the physico-chemical
properties of cement incorporating artificial pozzolan. The physicochemical
properties of cement at anhydrous state and the hydrated
state (chemical composition, specific weight, fineness, consistency of
the cement paste and setting times) were studied. The experimental
results obtained show that the quantity of pozzolanic admixture
(waste brick) of cement manufactured is the principal parameter who
influences on the variation of the physico-chemical properties of the
cement tested.
Abstract: In this paper by using the port-controlled Hamiltonian
(PCH) systems theory, a full-order nonlinear controlled model is first
developed. Then a nonlinear passivity-based robust adaptive control
(PBRAC) of switched reluctance motor in the presence of external
disturbances for the purpose of torque ripple reduction and
characteristic improvement is presented. The proposed controller
design is separated into the inner loop and the outer loop controller.
In the inner loop, passivity-based control is employed by using
energy shaping techniques to produce the proper switching function.
The outer loop control is employed by robust adaptive controller to
determine the appropriate Torque command. It can also overcome the
inherent nonlinear characteristics of the system and make the whole
system robust to uncertainties and bounded disturbances. A 4KW 8/6
SRM with experimental characteristics that takes magnetic saturation
into account is modeled, simulation results show that the proposed
scheme has good performance and practical application prospects.
Abstract: In this paper, we present a method named Signal Level
Matrix (SLM) which can improve the accuracy and stability of active
RFID indoor positioning system. Considering the accuracy and cost,
we use uniform distribution mode to set up and separate the
overlapped signal covering areas, in order to achieve preliminary
location setting. Then, based on the proposed SLM concept and the
characteristic of the signal strength value that attenuates as the
distance increases, this system cross-examines the distribution of
adjacent signals to locate the users more accurately. The experimental
results indicate that the adaptive positioning method proposed in this
paper could improve the accuracy and stability of the positioning
system effectively and satisfyingly.
Abstract: Ground-level tropospheric ozone is one of the air
pollutants of most concern. It is mainly produced by photochemical
processes involving nitrogen oxides and volatile organic compounds
in the lower parts of the atmosphere. Ozone levels become
particularly high in regions close to high ozone precursor emissions
and during summer, when stagnant meteorological conditions with
high insolation and high temperatures are common.
In this work, some results of a study about urban ozone
distribution patterns in the city of Badajoz, which is the largest and
most industrialized city in Extremadura region (southwest Spain) are
shown. Fourteen sampling campaigns, at least one per month, were
carried out to measure ambient air ozone concentrations, during
periods that were selected according to favourable conditions to
ozone production, using an automatic portable analyzer.
Later, to evaluate the ozone distribution at the city, the measured
ozone data were analyzed using geostatistical techniques. Thus, first,
during the exploratory analysis of data, it was revealed that they were
distributed normally, which is a desirable property for the subsequent
stages of the geostatistical study. Secondly, during the structural
analysis of data, theoretical spherical models provided the best fit for
all monthly experimental variograms. The parameters of these
variograms (sill, range and nugget) revealed that the maximum
distance of spatial dependence is between 302-790 m and the
variable, air ozone concentration, is not evenly distributed in reduced
distances. Finally, predictive ozone maps were derived for all points
of the experimental study area, by use of geostatistical algorithms
(kriging). High prediction accuracy was obtained in all cases as
cross-validation showed. Useful information for hazard assessment
was also provided when probability maps, based on kriging
interpolation and kriging standard deviation, were produced.
Abstract: This paper presents the approach to design the Auto-
Tuning PID controller for interactive Water Level Process using
integral step response. The Integral Step Response (ISR) is the
method to model a dynamic process which can be done easily,
conveniently and very efficiently. Therefore this method is advantage
for design the auto tune PID controller. Our scheme uses the root
locus technique to design PID controller. In this paper MATLAB is
used for modeling and testing of the control system. The
experimental results of the interacting water level process can be
satisfyingly illustrated the transient response and the steady state
response.
Abstract: Internet is largely composed of textual contents and a
huge volume of digital contents gets floated over the Internet daily.
The ease of information sharing and re-production has made it
difficult to preserve author-s copyright. Digital watermarking came
up as a solution for copyright protection of plain text problem after
1993. In this paper, we propose a zero text watermarking algorithm
based on occurrence frequency of non-vowel ASCII characters and
words for copyright protection of plain text. The embedding
algorithm makes use of frequency non-vowel ASCII characters and
words to generate a specialized author key. The extraction algorithm
uses this key to extract watermark, hence identify the original
copyright owner. Experimental results illustrate the effectiveness of
the proposed algorithm on text encountering meaning preserving
attacks performed by five independent attackers.
Abstract: In this paper we intend to ascertain the state of the art on multifingered end-effectors, also known as robotic hands or dexterous robot hands, and propose an experimental setup for an innovative task based design approach, involving cutting edge technologies in motion capture. After an initial description of the capabilities and complexity of a human hand when grasping objects, in order to point out the importance of replicating it, we analyze the mechanical and kinematical structure of some important works carried out all around the world in the last three decades and also review the actuators and sensing technologies used. Finally we describe a new design philosophy proposing an experimental setup for the first stage using recent developments in human body motion capture systems that might lead to lighter and always more dexterous robotic hands.
Abstract: In this paper, some common gearboxes vibration analysis methods and condition monitoring systems are explained. In addition, an experimental gearbox vibration analysis is discussed through a critical case history for a mixer gearbox related to Iran oil industry. The case history also consists of gear manufacturing (machining) recommendations, lubrication condition of gearbox and machinery maintenance activities that caused reduction in noise and vibration of the gearbox. Besides some of the recent patents and innovations in gearboxes, lubrication and vibration monitoring systems explained. Finally micro pitting and surface fatigue in pinion and bevel of mentioned horizontal to vertical gearbox discussed in details.
Abstract: The effect of the blade tip geometry of a high pressure
gas turbine is studied experimentally and computationally for high
speed leakage flows. For this purpose two simplified models are
constructed, one models a flat tip of the blade and the second models
a cavity tip of the blade. Experimental results are obtained from a
transonic wind tunnel to show the static pressure distribution along
the tip wall and provide flow visualization. RANS computations
were carried to provide further insight into the mean flow behavior
and to calculate the discharge coefficient which is a measure of the
flow leaking over the tip. It is shown that in both geometries of tip
the flow separates over the tip to form a separation bubble. The
bubble is higher for the cavity tip while a complete shock wave
system of oblique waves ending with a normal wave can be seen for
the flat tip. The discharge coefficient for the flat tip shows less
dependence on the pressure ratio over the blade tip than the cavity
tip. However, the discharge coefficient for the cavity tip is lower than
that of the flat tip, showing a better ability to reduce the leakage flow
and thus increase the turbine efficiency.
Abstract: This experiment discusses the effects of fracture
parameters such as depth, length, width, angle and the number of the
fracture to the conductance properties of laterite using the DUK-2B
digital electrical measurement system combined with the method of
simulating the fractures. The results of experiment show that the
changes of fracture parameters produce effects to the conductance
properties of laterite. There is a clear degressive period of the
conductivity of laterite during increasing the depth, length, width, or
the angle and the quantity of fracture gradually. When the depth of
fracture exceeds the half thickness of the soil body, the conductivity of
laterite shows evidently non-linear diminishing pattern and the
amplitude of decrease tends to increase. The length of fracture has
fewer effects than the depth to the conductivity. When the width of
fracture reaches some fixed values, the change of the conductivity is
less sensitive to the change of the width, and at this time, the
conductivity of laterite maintains at a stable level. When the angle of
fracture is less than 45°, the decrease of the conductivity is more
clearly as the angle increases. But when angle is more than 45°,
change of the conductivity is relatively gentle as the angle increases.
The increasing quantity of the fracture causes the other fracture
parameters having great impact on the change of conductivity. When
moisture content and temperature were unchanged, depth and angle of
fractures are the major factors affecting the conductivity of laterite
soil; quantity, length, and width are minor influencing factors. The
sensitivity of fracture parameters affect conductivity of laterite soil is:
depth >angles >quantity >length >width.
Abstract: Fatigue behaviors of Lead Zirconate Titanate (PZT)
ceramics under different amplitude of bipolar electrical loads have
been investigated. Fatigue behavior is represented by the change of
hysteresis loops and remnant polarization. Three levels of electrical
load amplitudes (1.00, 1.25 and 1.50 kV /mm) were applied in this
experimental. It was found that the remnant polarization decreased
significantly with the number of loading cycles. The degree of fatigue
degradation depends on the amplitude of electric field. The higher
amplitude exhibits the greater fatigue degradation.
Abstract: In this paper we have proposed three and two
stage still gray scale image compressor based on BTC. In our
schemes, we have employed a combination of four techniques
to reduce the bit rate. They are quad tree segmentation, bit
plane omission, bit plane coding using 32 visual patterns and
interpolative bit plane coding. The experimental results show
that the proposed schemes achieve an average bit rate of 0.46
bits per pixel (bpp) for standard gray scale images with an
average PSNR value of 30.25, which is better than the results
from the exiting similar methods based on BTC.
Abstract: This paper includes two novel techniques for skew
estimation of binary document images. These algorithms are based on
connected component analysis and Hough transform. Both these
methods focus on reducing the amount of input data provided to
Hough transform. In the first method, referred as word centroid
approach, the centroids of selected words are used for skew detection.
In the second method, referred as dilate & thin approach, the selected
characters are blocked and dilated to get word blocks and later
thinning is applied. The final image fed to Hough transform has the
thinned coordinates of word blocks in the image. The methods have
been successful in reducing the computational complexity of Hough
transform based skew estimation algorithms. Promising experimental
results are also provided to prove the effectiveness of the proposed
methods.
Abstract: In built-up structures, one of the effective ways of
dissipating unwanted vibration is to exploit the occurrence of slip at
the interfaces of structural laminates. The present work focuses on
the dynamic analysis of welded structures. A mathematical
formulation has been developed for the mechanism of slip damping
in layered and welded mild steel beams with unequal thickness
subjected to both periodic and non-periodic forces. It is observed that
a number of vital parameters such as; thickness ratio, pressure
distribution characteristics, relative slip and kinematic co-efficient of
friction at the interfaces, nature of exciting forces, length and
thickness of the beam specimen govern the damping characteristics of
these structures. Experimental verification has been carried out to
validate the analysis and study the effect of these parameters. The
developed damping model for the structure is found to be in fairly
good agreement with the measured data. Finally, the results of the
analysis are discussed and rationalized.
Abstract: Twenty four New Zealand white rabbits (12 does and
12 bucks) and twenty four Flanders (12 does and 12 bucks) rabbits,
allotted into two feeding regime (6 for each breed, 3 males and 3
females) first one fed commercial ration and second one fed
commercial diet plus sodium butyrate (300 g/ton). The obtained
results showed that at end of 8th week experimental period New
Zealand white rabbits were heavier body weight than Flanders rabbits
(1934.55+39.05 vs. 1802.5+30.99 g); significantly high body weight
gain during experimental period especially during 8th week
(136.1+3.5 vs. 126.8+1.8 g/week); better feed conversion ratio during
all weeks of experiment from first week (3.07+0.16 vs. 3.12+0.10)
till the 8th week of experiment (5.54+0.16 vs. 5.76+0.07) with
significantly high dressing percentages (0.54+0.01 vs. 0.52+0.01).
Also all carcass cuts were significantly high in New Zealand white
rabbits than Flanders. Females rabbits (at the same age) were lower
body weight than males from start of experiment (941.1+39.8
vs.972.1+33.5 g) till the end of experiment (1833.64+37.69 vs.
1903.41+36.93 g); gained less during all weeks of experiment except
during 8th week (132.1+2.3 vs. 130.9+3.4 g/week), with lower
dressing percentage (0.52+0.01 vs. 0.53+0.01) and lighter carcass
cuts than males, however, they had better feed conversion ratio
during 1st week, 7th week and 8th week of experiment. Addition of
300g sodium butyrate/ton of rabbit increased the body weight of
rabbits at the end of experimental period (1882.71+26.45 vs.
1851.5+49.82 g); improve body weight gain at 3rd, 4th, 5th, 6th and
7th week of experiment and significantly improve feed conversion
ratio during all weeks of the experiment from 1st week (2.85+0.07
vs. 3.30+0.15) till the 8th week of the experiment (5.51+0.12 vs.
5.77+0.12). Also the dressing percentage was higher in Sodium
butyrate fed groups than control one (0.53+0.01 vs. 0.52+0.01) and
the most important results of feeding sodium butyrate is the reducing
of the mortality percentage in rabbits during 8 week experiment to
zero percentage as compared with 16% in control group.
Abstract: The scattering effect of light in fog improves the
difficulty in visibility thus introducing disturbances in transport
facilities in urban or industrial areas causing fatal accidents or public
harassments, therefore, developing an enhanced fog vision system
with radio wave to improvise the way outs of these severe problems
is really a big challenge for researchers. Series of experimental
studies already been done and more are in progress to know the
weather effect on radio frequencies for different ranges. According to
Rayleigh scattering Law, the propagating wavelength should be
greater than the diameter of the particle present in the penetrating
medium. Direct wave RF signal thus have high chance of failure to
work in such weather for detection of any object. Therefore an
extensive study was required to find suitable region in the RF band
that can help us in detecting objects with proper shape. This paper
produces some results on object detection using 912 MHz band with
successful detection of the persistence of any object coming under the
trajectory of a vehicle navigating in indoor and outdoor environment.
The developed images are finally transformed to video signal to
enable continuous monitoring.